International Journal of Clinical Medicine, 2013, 4, 388-394
http://dx.doi.org/10.4236/ijcm.2013.49070 Published Online September 2013 (http://www.scirp.org/journal/ijcm)
P Wave Analysis in Patients with Sarcoidosis
Elias Gialafos1,2*, Elias Perros3*#, Aggeliki Rapti4, Theodore G. Papaioannou5, Vassilios Kouranos4,
Ioannis Moyssakis4, Konstantina Aggeli5, Georgios Dimopoulos6, Charalambos Kostopoulos3,
Eleftherios Stamboulis1, John Gialafos5, Christodoulos Stefanadis5, Nikolaos Koulouris2,
Myron Mavrikakis3
1Department of Neurology, University of Athens, Athens, Greece; 2Department of Pulmonology, University of Athens, Athens,
Greece; 3Department of Clinical Therapeutics, University of Athens, Athens, Greece; 4Outpatient Department of Sarcoidosis, Chest
Disease Hospital “Sotiria”, Athens, Greece; 5Department of Cardiology, University of Athens, Athens, Greece; 6Department of Criti-
cal Care Medicine, University of Athens, Athens, Greece.
Email: #eliasperros@yahoo.com
Received June 12th, 2013; revised July 16th, 2013; accepted August 5th, 2013
Copyright © 2013 Elias Gialafos et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Introduction: Atrial arrhythmias in patients with sarcoidosis (Sar) are not unusual and can occur due to either atrial
myocardial fibrosis and/or due to autonomic nervous system imbalance. Electrocardiographic markers (ECG), like
maximum and minimum P wave duration and P wave dispersion {Pdis = Pmax Pmin} reflect atrial depolarization inho-
mogeneity and can indicate patients prone to develop atrial arrhythmias while standard deviation of RR interval (SDNN)
is an index of heart rate variability, reflecting autonomic nervous system (ANS) activity. Methods: 90 patients with
sarcoidosis (41 males/49 females) enrolled in this multicenter prospective study underwent digital electrocardiography,
echocardiography and pulmonary function tests (PFTs). Diastolic and systolic indices of right and left ventricle were
measured echocardiographically including Doppler parameters while Pmax, Pmin, Pdis and SDNN were measured in a 5-
minute duration digital electrocardiogram. All consecutive patients were compared to 65 healthy volunteers (30
males/35 females). Results: Although heart rate and the echocardiographic indices were similar among the two groups,
the electrocardiographic indices were significantly prolonged in the patient group compared to controls. Maximum P
wave duration was correlated with SDNN (p < 0.05, r = 0.272) and the age of the patients (p < 0.05, r = 0.219) while
Pdis was correlated with SDNN (p < 0.001, r = 0.350) and the heart rate (p < 0.005, r = 0.323). Multivariate analysis
showed that Pmax and Pdis were independently correlated with SDNN. Conclusion: P wave dispersion is significantly
increased in patients with systemic sarcoidosis compared to healthy persons while maximum P wave duration and P
wave dispersion are negatively correlated with the standard deviation of RR, an index of heart rate variability implying
imbalance of ANS function. Further studies are needed for the clarification of the significance of this correlation.
Keywords: P Wave Analysis; Systemic Sarcoidosis; Autonomic Nervous System
1. Introduction
Sarcoidosis (Sar) is a systemic granulomatous disease of
unknown etiology characterized by variable clinical ma-
nifestations and an unpredictable course [1]. Myocardial
involvement is considered as a major contributor to mor-
tality in patients with sarcoidosis [2-4]. Cardiac manifes-
tations range from an incidentally identified, benign con-
dition to fatal cardiomyopathy causing cardiac arrhyth-
mias and sudden cardiac death [5,6]. Conduction abnor-
malities that range from first degree AV block to com-
plete heart block are the most common clinical manifes-
tations of cardiac involvement, with ventricular and atrial
arrhythmias being less frequent. Atrial arrhythmias have
an incidence of up to 19% with atrial tachycardia, atrial
flutter and atrial fibrillation being more common.
Simple electrocardiographic markers like maximum
(Pmax), minimum (Pmin ) and dispersion (Pdis) of P wave
are well known electrophysiological characteristics of
atria prone to fibrillate and are associated with inhomo-
geneous and discontinuous propagation of sinus impulses
[7,8]. P wave indices have been studied in several dis-
eases such as hypertension, aortic stenosis, dilated car-
diomyopathy and ischemia with common conclusion that
*Elias Gialafos and Elias Perros have contributed equally to this work.
#Corres
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P Wave Analysis in Patients with Sarcoidosis 389
prolongation of Pmax and P wave dispersion signifies in-
creased risk for the development of atrial fibrillation
[8-12]. Standard deviation of RR interval (SDNN) is an
index of heart rate variability and is considered as a pos-
sible marker of autonomic nervous system imbalance
[13].
The incidence of symptomatic cardiac involvement in
sarcoidosis is 5%, but autopsy material has shown at least
20% - 27% of the patients [14,15]. Atrial arrhythmias are
considered as one of the clinical criteria for the diagnosis
of cardiac sarcoidosis according to the Japanese ministry
criteria [16]. As a result, the identification of patients
prone to develop this kind of arrhythmia might play a
significant role in the treatment and alter the course of
the disease, since subclinical cardiac involvement may
play an important role in the disease’s progression and
prognosis.
This study was conducted in order to identify these pa-
tients with the use of P wave analysis.
2. Patients and Methods
2.1. Study Population
An observational case-control study was conducted with
patients from three university hospitals with biopsy
proven sarcoidosis between October 2002 and June 2004.
Presence of non caseating granulomas in the transbro-
chial biopsy, lymph node or skin biopsies confirmed the
diagnosis of sarcoidosis. The possibility of infection,
environmental factors or hypersensitivity reaction to
medication causing granulomatous inflammation had
been eliminated. Treatment with systemic glucocorti-
coids was not an exclusion criterion. Exclusion criteria
were the presence of chronic obstructive lung disease,
presence of arrhythmias, known coronary artery disease
or structural heart disease, systemic hypertension, diabe-
tes mellitus, pericarditis, pregnancy, alcoholism and the
presence of a previously implanted pacemaker. All con-
secutive patients were compared to a control group of
healthy asymptomatic volunteers with no comorbidities
and any past or present evidence of heart and/or lung
disease. None of the patients or control subjects was re-
ceiving any cardiac medication.
All consecutive patients underwent clinical assessment,
including determination of serum levels of angiotensin-
converting enzyme, 12-lead ECGs, radiologic chest stage
by radiography and transthoracic echocardiograms. Chest
radiographs were assessed to determine disease stage
using standard radiographic staging for sarcoidosis ac-
cording to the Scadding criteria: I, bilateral hilar lym-
phadenopathy (BHL) with normal lung parenchyma; II,
BHL and parenchymal infiltration; III bilateral infiltrates
without BHL and Stage IV pulmonary fibrosis/fibrocy-
stic parenchymal involvement [16]. Serum angiotensin
converting enzyme [SACE] as well as brain natriuretic
peptide (BNP, Triage, ROCHE), an estimator of diastolic
function in the left ventricle, were measured. High SACE
activity was defined as concentration higher than 55 U/L
and was considered to reflect disease activity [18,19],
while BNP higher than 100 pg/dl implied diastolic heart
failure (Table 1). Control subjects underwent complete
echocardiographic and electrocardiographic study. The
study protocol was approved by the institutional ethics
committee and informed consent was obtained from all
the study subjects.
2.2. Pulmonary Evaluation
Pulmonary function tests (PFTs) including Forced Expi-
ratory Volume at 1 sec (FEV1), Forced Vital Capacity
(FVC), the ratio of FEV1/FVC and the Total Lung Ca-
pacity (TLC) were performed with a body box plethys-
mograph while Diffusing Capacity for Carbon Monoxide
(DLCO) was measured by the single breath method.
Values were expressed as a percentage of those pre-
dicted.
2.3. Standard Echocardiography
An echocardiographic study was performed for all par-
ticipants in the same echo lab with the patients in partial
left decubitus position by an expert sonographer using a
commercially available ultrasonic device (Hewlett-Pack-
ard, Sonos 5500, Andover, Massachusetts). All M-mode,
two dimensional and Doppler images were recorded with
a S3 transducer. Two-dimensional guided M-mode quan-
titative left ventricular analysis was performed in the
parasternal short-axis view, according to the recommen-
dations of the American Society of Echocardiography.
[20] Left atrial (LA), diastolic (LVEDD) and systolic
(LVESD) ventricular dimensions were measured. Left
ventricular Ejection Fraction (EF) was determined by the
biplane Simpson’s method, [21] whereas LV mass by the
Penn Conversion Formula. [22] Pulsed Doppler record-
ings were obtained during transmitral and transtricuspi-
dal flow and the following parameters were measured:
maximal velocity of early diastolic filling (Em) or (Et),
late diastolic filling (Am) or (At) and the ratio of early to
late diastolic filling velocities (m
EA or t
EA ) in mi-
tral or tricuspid valve, respectively. Furthermore, Decel-
eration Time (DT) and Isovolumic Relaxation Time
(IVRT) of mitral and tricuspid valves were measured.
2.4. 12-Lead S u rf a c e ECG
In all participants, a 12 lead digital ECG was recorded in
the supine resting position using a computer-based ECG
system (CardioControl NV, the Netherlands). The 12
leads of ECG were recorded simultaneously at a sam-
pling rate of 1200 Hz for 5 minutes. During each re-
Copyright © 2013 SciRes. IJCM
P Wave Analysis in Patients with Sarcoidosis
Copyright © 2013 SciRes. IJCM
390
Table 1. Baseline demographic and clinical patients’ and controls’ characteristics, ultrasound and electrocardiographic pa-
rameters among groups of patients with and without therapy and controls.
Patients Total patients Without therapy (n = 53) With therapy (n = 37) Controls
Males/Females 41/49 25/28 16/21 30/35
Age (years) 48 ± 13 50.21 ± 12.99 49.88 ± 13 44 ± 9
BMI (Kg/m2) 28 ± 5 27.93 ± 4.5 27.69 ± 5.55 26 ± 6
Smokers 24 13 11 18
SACE (U/L) 44 ± 25 46.76 ± 25 46.52 ± 28
Brain Natriuretic Peptide (pg/dl) 17 ± 15 19.95 ± 22.69 23.26 ± 28.37 15.8 ± 14.3
Systolic Arterial Pressure (mmHg) 122 ± 16 126.34 ± 16.85 119.04 ± 15.38 119 ± 17
Ultrasound Parameters
Left Atrium (mm) 38 ± 5 37.7 ± 4.12 38.38 ± 4.86 36 ± 7
LV End Diastolic Diameter (mm) 50 ± 4 49.62 ± 3.97 50.31 ± 3.24 45 ± 5
Mitral E wave 0.7 ± 0.1 0.7 ± 0.12 0.66 ± 0.13 0.9 ± 0.2
Mitral A wave 0.67 ± 0.1 0.69 ± 0.143 0.69 ± 0.125 0.5 ± 0.2
Mitral Deceleration Time (ms) 180 ± 26 177.09 ± 25.51 177.96 ± 21.29 185 ± 35
Mitral E/A wave 1.08 ± 0.32 1.09 ± 0.31 1.03 ± 0.33 1.2 ± 0.4
Tricuspidal E wave 0.5 ± 0.1 0.5 ± 0.08 0.49 ± 0.07 0.6 ± 0.2
Tricuspidal A wave 0.49 ± 0.135 0.51 ± 0.147 0.5 ± 0.1 0.4 ± 0.125
Tricuspidal E/A 1.08 ± 0.34 1.08 ± 0.35 1.04 ± 0.28 1.2 ± 0.35
Tricuspidal Deceleration Time (ms) 200 ± 38 177.09 ± 25.51 177.96 ± 21.29 195 ± 40
Ejec. Fraction (%) 57 ± 5 61.49 ± 8.59 62.14 ± 7.88 61 ± 6
Left Ventricular Mass (mg) 206 ± 56 202.85 ± 57 215.6 ± 50.21 195 ± 13
Electrocardiographic Parameters
HR(bpm) 76 ± 12 77.76 ± 12.36 75.96 ± 11.43 74 ±11
Pmax (ms) 120 ± 14* 122.15 ± 11.47* 116.54 ± 15.72* 97 ± 11
Pmin (ms) 76 ± 12* 76.67 ± 11.81* 76.06 ± 13.16* 59 ± 17
Pdis (ms) 44 ± 13* 45.48 ± 12.41* 40.48 ± 12.56* 38 ± 10
Standard Deviation Of RR 60 ± 50* 54.93 ± 45.27* 63.57 ± 54.49* 90 ± 25
*Statistical significant (p < 0.05).
cording, the subjects remained silent and breathed freely.
From each lead, the average complex was calculated by
the modular ECG analysis system (MEANS). Individual
average complexes were stored digitally. The mean heart
rate (HR) was calculated. The standard deviation of nor-
mal R-R interval (SDNN) in the 5 minute ECG recording
was used as a short-term heart rate variability index.
2.5. P Wave Measurements
The averaged stored ECG’s of patients and controls were
displayed on a high resolution computer screen. Each
averaged complex in each lead was separately magnified
at a magnification of 160 mm/s and 60 mm/mV. The
onset and offset of the P wave were defined as the junc-
tion between the P wave pattern and the isoelectric line
and were marked with a cursor. If the baseline noise was
>10 µV and/or the peak to isoelectric line P wave ampli-
tude <15 µV, the lead was excluded from the analysis.
Two independent investigators measured the P waves
without access to other information. The measurements
of the two observers were averaged. Subjects with P
waves measurable <9 ECG leads were excluded from the
analysis.
2.6. Definition of ECG Analysis Indices
The following indices were derived from each measure-
ment of each ECG:
1) The maximum P wave duration in any of the meas-
urable leads (Pmax).
2) The minimum P wave duration in any of the meas-
urable leads (Pmin).
3) P wave dispersion (Pdis), defined as the difference
between Pmax and Pmin .
4) Standard Deviation of RR (SDNN), was calculated
P Wave Analysis in Patients with Sarcoidosis 391
and used as an indirect index of autonomic nervous sys-
tem.
2.7. Accuracy of the Measurements
Intra-observer and inter-observer mean percentage errors
(absolute difference between two observations divided
by the mean and expressed as a percentage for P-wave
duration measurements were determined in 30 randomly
selected study participants and were less than 10% in all
leads.
2.8. Statistical Analysis
Statistical analysis was carried out with a commercially
available statistical software package. Continuous data
are reported as mean ± SD. Continuous variables were
normally distributed as indicated by the Kolmogorov-
Smirnov 1-sample test except standard deviation of RR,
which was log-transformed. Differences between the two
groups were evaluated by using the Student’s unpaired
t-test for continuous and χ2 test for categorical variables.
Bivariate correlations were calculated with Pearson’s
product moment method. Analysis of variance (one way
ANOVA) was performed for ECG parameters among
different stages of sarcoidosis and Scheffe’s adjustment
was performed in order to correct the significant differ-
ences among multiple comparisons. Stepwise multivari-
ate linear regression analysis was performed to estimate
independent determinants of P wave indices. P value of
<0.05 was assumed to represent statistical significance.
3. Results
3.1. Patient Characteristics
Among 106 consecutive patients referred for possible
enrollment into the study, fifty met the criteria and 16
were excluded due to arterial hypertension (8 patients),
chronic obstructive pulmonary disease (6 patients) and
cardiac arrhythmias (2 patients). The remaining 90 pa-
tients (41 males/49 females) were compared to 65
healthy volunteers (30 males/35 females). Patients’ and
controls’ characteristics are presented in Table 1. The
mean age of patients was 48 ± 13 years and that of the
control group was 44 ± 9 years. The mean duration of the
disease was 4.3 ± 5.6 years. Both the compared groups
were age, sex, BMI and smoking matched (Table 1).
Fifty nine patients (65.5%) were classified as stage I,
fifteen patients (17%) stage II, five (5.5%) at stage III
while eleven (12%) patients were at stage IV. Thirty six
patients (40%) were currently under cortisone treatment
while additionally twenty six (28.9%) had received cor-
tisone treatment in the past (mean capture time of corti-
sone: 12 ± 7 months). The average level of SACE was
within normal range while only twenty four patients
(27%) had increased levels of SACE. Twenty four pa-
tients (27%) were currently smokers. No significant dif-
ferences were observed between sarcoidosis and control
group concerning heart rate, blood pressure (Systolic and
Diastolic) as well as echocardiographic indices (Table
1).
3.2. Pulmonary Evaluation
Pulmonary function tests showed impairment of lung
function in 43 (48%) patients. More specific, the aver-
aged values (% of the predicted values) were FEV1: 94 ±
19%, FVC: 97 ± 19%, FEV1/FVC: 92 ± 11, TLC = 87 ±
15% and DLCO = 85 ± 18%. Restrictive pattern (DLCO
< 80%, TLC < 80%) was present in 25 (29%), isolated
DLCO reduction in 12 (13%), obstructive pattern
(FEV/FVC < 70%) and mixed form (DLCO < 80%, TLC
< 80%, FEV/FVC < 70%) in 6 (6.6%) patients.
3.3. P Wave Indices
Measurements of maximum, minimum and dispersion of
P wave in the two study groups are presented in Table 1.
More specific, P maximum (120 ± 14 vs 97 ± 11, p <
0.001), P minimum (76 ± 12 vs 59 ± 171, p < 0.001), P
wave dispersion (44 ± 18 vs 38 ± 10, p < 0.001) and
SDNN (60 ± 50 vs 90 ± 25, p < 0.005) were found to be
significantly different in patient group than in controls.
Further analysis of the patient group concerning P wave
indices didn’t show significant differences among the
patients’ groups of disease staging or the groups based on
corticosteroid treatment uptake. Significant prolongation
of Pmax (123 ± 15 msec vs 116 ± 11, p = 0.035) and Pmin
(79 ± 13 msec vs 73 ± 11, p < 0.041) was seen in those
patients with levels of SACE higher than 55 U/L com-
pared to those with levels of SACE less than 54 U/L. In
bivariate analysis performed in patients group, ECG in-
dices, cardiac ultrasound indices, biochemical variables
and pulmonary parameters were included. Maximum P
wave was found negatively correlated to SDNN (p <
0.005, r = 0.305) and positively correlated to the age of
the patients (p = 0.042, r = 0.212), while minimum P
wave was not related with any parameter. P wave disper-
sion was correlated positively with HR (p = 0.003, r =
0.323) and negatively with SDNN (p < 0.001, r =
0.388). Multivariate stepwise regression analysis show-
ed that maximum P wave was independently related only
with the SDNN (p = 0.005, β = 0.305), while P wave
dispersion was independently related with HR (p = 0.09,
β = 0.193) and SDNN (p = 0.006, β = 0.318).
4. Discussion
The main finding of this study was that patients with
sarcoidosis have significant higher values of maximum,
minimum and dispersion of P wave on the surface ECG
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P Wave Analysis in Patients with Sarcoidosis
392
compared to those of healthy individuals. Also, SDNN
was significant decreased in patient’s group, implying a
functional imbalance between sympathetic and para-
sympathetic system in favor of the former [23]. Of great
importance is the finding that these indices did not im-
prove with corticosteroid treatment and that they were
not influenced by the stage of the disease while pro-
longed P wave was observed in patients with higher lev-
els of SACE. P wave analysis studies have been utilized
in various diseases for the assessment of arrhythmia’s
risk [7-12,21,24]. To our knowledge this is the first study
that uses P wave analysis in patients with sarcoidosis.
P wave represents the electrical activation of both atria,
which takes place sequentially from right to left atrium. P
wave duration is, among others, determined by the fol-
lowing factors: 1) Atrial conduction velocity, which is
non uniform, 2) the length of the longest pathway be-
tween the right atrial site of impulse origin or sinus node
and the latest area to be activated, which is typically the
lateral left atrium; and 3) although not generally appre-
ciated, both P-wave duration and morphology are not
static, but dynamic, and change with shifts in the sites of
the predominant atrial pacemaker [25]. The association
between atrial arrhythmias and P wave analysis during
periods of sinus rhythm is well established [7-12,21,24].
The relationship of prolonged P wave indices to atrial
arrhythmias has clinical significance since prolonged
conduction can provide an etiologic basis for the ap-
pearance of atrial arrhythmias. Turgut et al. showed that
prolonged atrial conduction was a predisposing factor for
the development of atrial flutter [26]. Susceptibility to
this type of arrhythmias is present when there exists ab-
errant conduction between the atria. Prolongation of Pdur
may possibly indicate the presence of intra- or inter-atrial
conduction disturbance and inhomogeneous spread can
occur independently of the increase in atrial dimensions.
Indeed, in this study no correlation was observed be-
tween P wave analysis indicis and left atrium.
Recently, P wave dispersion, defined as the difference
between maximum and minimum P wave duration in 12
lead ECG, has been used to separate patients with a high
risk of AF while on sinus rhythm [7,8]. Previous studies
revealed the significantly higher values of Pmax and Pdis in
patients with paroxysmal atrial fibrillation, either idio-
pathic or due to hypertension compared to those of
healthy subjects while another study showed that Pmax
was a significant independent predictor of the recurrence
of the arrhythmias [7,8,21].
Another important finding was the negative correlation
of P wave indices with the SDNN, a marker of heart rate
variability [13,23,27]. This relationship is in agreement
with another work that showed reduced values of high
frequency spectral components of heart rate variability,
implying altered sympatho-vagal balance due to de-
creased parasympathetic tone caused by changes of res-
piratory pattern in patients with sarcoidosis [13]. P wave
duration and P wave dispersion have been reported to be
influenced by the autonomic tone, which induces changes
in the velocity of impulse propagation [28]. In addition,
another study showed that increased sympathetic activity
causes a significant increase in P wave dispersion. [29]
As a result of these findings, the authors can suggest that
the imbalance between the parasympathetic and sympa-
thetic systems may be an underlying cause of higher va-
lues of P wave maximum and dispersion in sarcoidosis.
It is important to note that the authors observed pro-
longation of P wave indices in patients with increased
level of SACE, implying concordance with the severity
of the disease and a dynamic nature of P wave, which
responds to fluctuations in pulmonary function tests and
in the disease activity. In addition renin-angiotensin-
aldosterone system has been found to promote atrial fib-
rillation by enhancing atrial myocardial fibrosis [30].
Moreover although it is uncertain whether captopril, a
well known ACE inhibitor, suppresses the production of
ACE enhanced from macrophages in the granulomatous
lesion, studies have demonstrated inhibition of serum
ACE activity with subsequent decrease in plasma angio-
tensin and aldosterone, indicating that captopril may of-
fer an effective therapeutic approach to the treatment of
active stage of sarcoidosis [31].
On the other hand, Asad et al showed a rapid reversal
of P wave characteristics responding to therapy in pa-
tients with Chronic Obstructive Lung Disease [32]. Fur-
thermore, Carilli et al showed in a retrospective study the
predictive value of P-wave amplitude and axis in esti-
mating the severity of nonasthmatic airway obstructive
disease in the quiescent state and they demonstrated a
good correlation of P wave amplitude and axis with
FEV1/FVC and the residual volume/total lung capacity
in a continuous regression equation [33]. These findings
show that P-wave analysis may be used in estimating the
progression of the disease severity in multiple diseases.
Identification of patients with sarcoidosis that are
prone for cardiac arrhythmias is important since the
prognosis of sarcoidosis is mainly determined by pul-
monary and cardiac manifestations and is improved by
aggressive treatment [34]. Moreover, studies have shown
that survival of the patients was limited to 2 years after
the development of cardiac symptoms while 67% of the
patients of them died suddenly [35]. The principal histo-
logical features of heart involvement in sarcoidosis in-
clude increased fibrotic activity, lymphocyte infiltration,
interstitial edema and presence of granulomas which
show a localized distribution within the myocardium [36].
Postmortem studies have revealed the presence of vari-
ous amounts of myocardial scar tissue, which is consid-
ered to provide the substrate for supraventricular and
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P Wave Analysis in Patients with Sarcoidosis 393
ventricular arrhythmias. Deranged microarchitecture and
non-uniform anisotropic properties of the atrial myocar-
dium may cause inhomogeneous and discontinuous pro-
pagation of sinus impulses. In addition to this effect of
atrial fiber geometry on the impulse propagation, other
intracellular or intercellular factors might account for the
non-uniform anisotropic conduction of the atrial myocar-
dium such as the presence of site-specific conduction
delays. Expression of these pathologic findings in the
ECG can be found in as many as 50% of patients even
without clinical evidence of cardiac involvement, with
repolarization changes, arrhythmias and conduction dis-
turbances being the most frequent.
The main limitation of the study is the absence of fol-
low-up. This might have been necessary in order to
evaluate these indices as predictors of future arhythmic
events in this setting of patients and establish their clini-
cal significance. Also, although structural inhomogeneity
in ultra-structural properties is considered to play a major
role in the initiation of reentrant circuits due to the in-
creased likelihood of unidirectional block of the prema-
ture impulse, the study showed no correlation between
the atrial size and P-wave regarding the atrial structure
[33]. Data regarding these indices are not available for
the period before the study. These data could show this
correlation.
5. Conclusion
Patients with sarcoidosis, in comparison to the control
subjects, displayed increased values of Pmax, Pmin and Pdis
possibly reflecting an effect of the disease while an in-
verse correlation with SDNN was established implying
an imbalance of autonomic nervous system activity. Pro-
longation of Pmax and P wave dispersion and autonomic
nervous system imbalance signified increased risk for the
development of atrial fibrillation, a major clinical crite-
rion of cardiac involvement in patients with systemic
sarcoidosis. This might be of importance, since identifi-
cation of patients prone to develop arrhythmias played a
role in the treatment and altered the course of the disease.
6. Acknowledgements
There was no funding or sponsorship for the design,
preparation and completion of this study. There were no
financial or other relationships for each author for the
design, preparation and completion of this study. We
have to acknowledge the assistance of Mrs Andrioti
Roula, Drakopoulou Ioanna and Gialafou Irene for their
assistance for the preparation of this manuscript.
REFERENCES
[1] Joint Statement of the American Thoracic Society (ATS),
the European Respiratory Society (ERS) and the World
Association of Sarcoidosis and Other Granulomatous
Disorders (WASOG) adopted by the ATS Board of Di-
rectors and by the ERS Executive Committee, “Statement
on Sarcoidosis,” American Journal of Respiratory and
Critical Care Medicine, Vol. 160, No. 2, 1999, pp. 736-
755. doi:10.1164/ajrccm.160.2.ats4-99
[2] D. Mehta, S. A. Lubitz, Z. Frankel, et al., “Cardiac In-
volvement in Patients with Sarcoidosis: Diagnostic and
Prognostic Value of Outpatient Testing,” Chest, Vol. 133,
No. 6, 2008, pp. 1426-1435. doi:10.1378/chest.07-2784
[3] M. R. Patel, P. J. Cawley, J. F. Heitner, et al., “Detection
of Myocardial Damage in Patients with Sarcoidosis,” Cir-
culation, Vol. 120, No. 20, 2009, pp. 1969-1977.
[4] A. Perry and F. Vuitch, “Causes of Death in Patients with
Sarcoidosis. A Morphologic Study of 38 Autopsies with
Clinicopathologic Correlations,” Archives of Pathology &
Laboratory Medicine, Vol. 119, No. 2, 1995, pp. 167-172.
[5] J. C. Deng, R. P. Baughman and J. P. Lynch, “Cardiac In-
volvement in Sarcoidosis,” Seminars in Respiratory and
Critical Care Medicine, Vol. 23, No. 6, 2002, pp. 513-
527. doi:10.1055/s-2002-36516
[6] B. Pierre-Louis, A. Prasad and W. H. Frishman, “Cardiac
Manifestations of Sarcoidosis and Therapeutic Options,”
Cardiology in Review, Vol. 17, No. 4, 2009, pp. 153-158.
doi:10.1097/CRD.0b013e3181a1f763
[7] K. Aytemir, N. Ozer, E. Atalar, et al., “P Wave Disper-
sion on 12-Lead Electrocardiography in Patients with Par-
oxysmal Atrial Fibrillation,” Pacing and Clinical Electro-
physiology, Vol. 23, No. 7, 2000, pp. 1109-1112.
doi:10.1111/j.1540-8159.2000.tb00910.x
[8] P. E. Dilaveris, E. J. Gialafos, S. K. Sideris, et al., “Sim-
ple Electrocardiographic Markers for the Prediction of
Paroxysmal Idiopathic Atrial Fibrillation,” American Heart
Journal, Vol. 135, No. 5, 1998, pp. 733-738.
doi:10.1016/S0002-8703(98)70030-4
[9] P. E. Dilaveris, G. K. Andrikopoulos, G. Metaxas, et al.,
“Effects of Ischemia on P Wave Dispersion and Maxi-
mum P Wave Duration during Spontaneous Anginal Epi-
sodes,” Pacing and Clinical Electrophysiology, Vol. 22,
No. 11, 1999, pp. 1640-1647.
doi:10.1111/j.1540-8159.1999.tb00384.x
[10] A. Dogan, M. Ozaydin, C. Nazli, et al., “Does Impaired
Left Ventricular Relaxation Affect P Wave Dispersion in
Patients with Hypertension?” Annals of Noninvasive Elec-
trocardiology, Vol. 8, No. 3, 2003, pp. 189-193.
doi:10.1046/j.1542-474X.2003.08304.x
[11] F. Ozmen, E. Atalar, K. Aytemir, et al., “Effect of Bal-
loon-Induced Acute Ischaemia on P Wave Dispersion
during Percutaneous Transluminal Coronary Angioplasty,”
Europace, Vol. 3, No. 4, 2001, pp. 299-303.
doi:10.1053/eupc.2001.0187
[12] H. Turhan, E. Yetkin, R. Atak, et al., “Increased P-Wave
Duration and P-Wave Dispersion in Patients with Aortic
Stenosis,” Annals of Noninvasive Electrocardiology, Vol.
8, No. 1, 2003, pp. 18-21.
doi:10.1046/j.1542-474X.2003.08104.x
[13] J. Sztajzel, “Heart Rate Variability: A Noninvasive Elec-
trocardiographic Method to Measure the Autonomic Ner-
Copyright © 2013 SciRes. IJCM
P Wave Analysis in Patients with Sarcoidosis
Copyright © 2013 SciRes. IJCM
394
vous System,” Swiss Medical Weekly, Vol. 134, No. 35-
36, 2004, pp. 514-522
[14] J. Habersberger, V. Manins and A. J. Taylor, “Cardiac
Sarcoidosis,” Internal Medicine Journal, Vol. 38, No. 4,
2008, pp. 270-277.
doi:10.1111/j.1445-5994.2007.01590.x
[15] F. Tavora, N. Cresswell, L. Li, et al., “Comparison of
Necropsy Findings in Patients with Sarcoidosis Dying
Suddenly from Cardiac Sarcoidosis versus Dying Sud-
denly from Other Causes,” American Journal of Cardiol-
ogy, Vol. 104, No. 4, 2009, pp. 571-577.
doi:10.1016/j.amjcard.2009.03.068
[16] H. Hiraga, K. Yuwai, M. Hiroe, et al., “Guidelines for the
Diagnosis of Cardiac Sarcoidosis: Study Report of Dif-
fuse Pulmonary Diseases,” Japanese Ministry of Health
and Welfare, Tokyo, 1993, pp. 23-24.
[17] G. W. Hunninghake, U. Costabel, M. Ando, et al., “ATS/
ERS/WASOG Statement on Sarcoidosis,” Sarcoidosis,
Vasculitis and Diffuse Lung Diseases, Vol. 16, No. 2,
1999, pp. 149-173.
[18] K. Sugisaki, T. Yamaguchi, S. Nagai, et al., “Clinical Cha-
racteristics of 195 Japanese Sarcoidosis Patients Treated
with Oral Corticosteroids,” Sarcoidosis, Vasculitis and Dif-
fuse Lung Diseases, Vol. 20, No. 3, 2003, pp. 222-226.
[19] M. Tahir, S. K. Sharma, S. Ashraf and H. K. Mishra,
“Angiotensin Converting Enzyme Genotype Affects De-
velopment and Course of Sarcoidosis in Asian Indians,”
Sarcoidosis, Vasculitis and Diffuse Lung Diseases, Vol. 24,
No. 2, 2007, pp. 106-112.
[20] N. B. Schiller, P. M. Shah, M. Crawford, et al., “Recom-
mendations for Quantitation of the Left Ventricle by
Two-Dimensional Echocardiography. American Society
of Echocardiography Committee on Standards, Subcom-
mittee on Quantitation of Two-Dimensional Echocardio-
grams,” Journal of the American Society of Echocardi-
ography, Vol. 2, No. 5, 1989, pp. 358-367.
[21] P. E. Dilaveris, E. J. Gialafos, D. Chrissos, et al., “Detec-
tion of Hypertensive Patients at Risk for Paroxysmal At-
rial Fibrillation during Sinus Rhythm by Computer-As-
sisted P Wave Analysis,” Journal of Hypertension, Vol.
17, No. 10, 1999, pp. 1463-1470.
doi:10.1097/00004872-199917100-00015
[22] S. F. Nagueh, “Echocardiographic Assessment of Left
Ventricular Relaxation and Cardiac Filling Pressures,”
Current Heart Failure Reports, Vol. 6, No. 3, 2009, pp.
154-159. doi:10.1007/s11897-009-0022-8
[23] S. Lucreziotti, A. Gavazzi, L. Scelsi, et al., “Five-Minute
Recording of Heart Rate Variability in Severe Chronic
Heart Failure: Correlates with Right Ventricular Function
and Prognostic Implications,” American Heart Journal,
Vol. 139, No. 6, 2000, pp. 1088-1095.
doi:10.1067/mhj.2000.106168
[24] K. Senen, H. Turhan, A. Riza Erbay, et al., “P-Wave Du-
ration and P-Wave Dispersion in Patients with Dilated
Cardiomyopathy,” European Journal of Heart Failure,
Vol. 6, No. 5, 2004, pp. 567-569.
[25] J. Boineau, “The Prolonged P Wave and Interatrial Block.
Time to Consider a Broader Concept and Different Ter-
minology,” Journal of Electrocardiology, Vol. 38, No. 4,
2005, pp. 327-329.
doi:10.1016/j.jelectrocard.2005.05.002
[26] O. Turgut, I. Tandogan, M. B. Yilmaz, et al., “Associa-
tion of P Wave Duration and Dispersion with the Risk for
Atrial Fibrillation: Practical Considerations in the Setting
of Coronary Artery Disease,” International Journal of
Cardiology, Vol. 144, No. 2, 2010, pp. 322-324.
doi:10.1016/j.ijcard.2009.03.023
[27] R. L. Verrier and C. Antzelevitch, “Autonomic Aspects of
Arrhythmogenesis: The Enduring and the New,” Current
Opinion in Cardiology, Vol. 19, No. 1, 2004, pp. 2-11.
doi:10.1097/00001573-200401000-00003
[28] A. N. Cheema, M. W. Ahmed, A. H. Kadish and J. J.
Goldberger, “Effects of Autonomic Stimulation and Block-
ade on Signal-Averaged P Wave Duration,” Journal of
the American College of Cardiology, Vol. 26, No. 2, 1995,
pp. 497-502. doi:10.1016/0735-1097(95)80028-F
[29] T. Tukek, V. Akkaya, S. Demirel, et al., “Effect of Val-
salva Maneuver on Surface Electrocardiographic P-Wave
Dispersion in Paroxysmal Atrial Fibrillation,” American
Journal of Cardiology, Vol. 85, No. 7, 2000, pp. 896-899.
doi:10.1016/S0002-9149(99)00891-7
[30] R. Ramaraj, “Role of the Renin-Angiotensin System in
the Promotion of Atrial Fibrillation,” Acta Cardiologica,
Vol. 64, No. 6, 2009, p. 843.
doi:10.2143/AC.64.6.2044757
[31] K. Mizuno, M. Gotoh, J. Matsui, et al., “Acute Effects of
Captopril on Serum Angiotensin-Converting Enzyme Ac-
tivity, the Renin-Aldosterone System and Blood Pressure
in Patients with Sarcoidosis,” The Tohoku Journal of Ex-
perimental Medicine, Vol. 140, No. 1, 1983, pp. 107-108.
doi:10.1620/tjem.140.107
[32] N. Asad, V. M. Johnson and D. H. Spodick, “Acute Right
Atrial Strain: Regression in Normal as Well as Abnormal
P-Wave Amplitudes with Treatment of Obstructive Pul-
monary Disease,” Chest, Vol. 124, No. 2, 2003, pp. 560-
564. doi:10.1378/chest.124.2.560
[33] O. A. Centurion, “Clinical Implications of the P Wave
Duration and Dispersion: Relationship between Atrial Con-
duction Defects and Abnormally Prolonged and Fraction-
ated Atrial Endocardial Electrograms,” International Jour-
nal of Cardiology, Vol. 134, No. 1, 2009, pp. 6-8.
doi:10.1016/j.ijcard.2008.12.072
[34] Y. Yazaki, M. Isobe, M. Hiroe, et al., “Prognostic Deter-
minants of Long-Term Survival in Japanese Patients with
Cardiac Sarcoidosis Treated with Prednisone,” American
Journal of Cardiology, Vol. 88, No. 9, 2001, pp. 1006-
1010. doi:10.1016/S0002-9149(01)01978-6
[35] V. V. Suranagi, P. R. Malur and H. B. Bannur, “Cardiac
Sarcoidosis Causing Sudden Death,” Indian Journal of
Pathology and Microbiology, Vol. 52, No. 4, 2009, pp.
566-567. doi:10.4103/0377-4929.56170
[36] A. Uemura, S. Morimoto, S. Hiramitsu, et al., “Histologic
Diagnostic Rate of Cardiac Sarcoidosis: Evaluation of
Endomyocardial Biopsies,” American Heart Journal, Vol.
138, No. 2, 1999, pp. 299-302.
doi:10.1016/S0002-8703(99)70115-8