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NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810
NJMR│Volume 6│Issue 2│Apr – Jun 2016 Page 181
ORIGINAL ARTICLE
P-WAVE ABNORMALITIES IN PATIENTS OF STABLE
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
Shriharshavardhan S V1, Malay Sarkar2, Arvind Kandoria3, Rameshwar S Negi4, Sunil Sharma5
Author’s Affiliations: 1 Postgraduate Resident; 2Professor & Head; 4Associate Professor; 5Assistant Professor, Dept of
Pulmonary Medicine; 3Associate Professor, Dept. of Cardiology, IGMC, Shimla, Himachal Pradesh, India
Correspondence: Dr Shriharshavardhan S V Email: harsha218@gmail.com
ABSTRACT
Introduction: COPD is a common preventable and treatable disease and a major cause of morbidity and
mortality globally. ECG is a very simple, widely available and convenient bedside investigation that can be
used to detect various cardiac abnormalities. Electrical activities of the heart are often influenced by COPD.
ECG changes like P-wave abnormalities have to be carefully assessed before coming to an inference.
Methodology: The present study was an institutional based prospective study, conducted from July 2014 to
June 2015. The study was designed to assess the various ECG abnormalities in stable COPD patients and to
determine echocardiography findings in relation to ECG changes.
Results: Among the P-wave abnormalities P-wave axis verticalisation (PWAV) was observed in 59(76.6%)
patients. Twenty (26%) patients showed negative P-wave in V1, significant-Ptf(P-terminal force) was observed
in 3(3.9%) patients. P-mitrale was seen in 18(31.2%), and P-pulmonale in 16 (20.8%) patients.
Conclusion: Though not specific, ECG may reveal various functional and structural abnormalities of the
heart in relation to COPD like PWAV. PWAV may be the most commonly seen P-wave abnormalities in
COPD patients. Echocardiography findings suggest that presence of P-mitrale is not conclusive of left atrial
overload in patients of COPD. Echocardiography should be done routinely in all COPD patients to confirm
ECG findings and to diagnose pulmonary hypertension, cor-pulmonale and other subclinical cardiovascular
co-morbidities like left ventricular diastolic dysfunction.
Keywords: Chronic obstructive pulmonary disease, ECG, Echocardiography, P-wave axis verticalisation
INTRODUCTION
COPD is an important public health problem and a
major cause of morbidity and mortality in both de-
veloped and developing countries. Exacerbations and
Comorbidities contribute to the overall severity in
individual patients.1 Cardiovascular co-morbidities
are particularly common in COPD2. In mild to mod-
erate COPD, cardiovascular disease is the leading
cause of hospitalization and second leading cause of
mortality after lung cancer, contributing to 25% of
the total COPD death.3 However, in advanced
COPD, respiratory failure is the main cause of mor-
tality.4 Screening for cardiovascular co-morbidities
should be an important component in the manage-
ment of COPD as they can worsen the clinical status
and prognosis of COPD patients. COPD also influ-
ences the electrical events of the heart. ECG is a very
simple, widely available and convenient bedside in-
vestigation that can be used to detect various cardiac
abnormalities in COPD patients.5 Right atrial en-
largement(RAE) may be expressed as P-Pulmonale,
P-wave axis verticalisation(PWAV), significant-Ptf
(P-terminal force). The frontal PWAV (P-axis > 60°)
has a close correlation with emphysema and may be
an early finding of worsening of COPD before oc-
currence of other ECG changes of right heart hyper-
trophy and enlargement, such as P-pulmonale. In-
creasing verticality of the frontal P-vector correlates
with increasing degree of airway obstruction, degree
of depression of the diaphragm and radiographic
quantification of the disease.6-9 The Ptf is one of the
P-wave indices affected by COPD, it is considered as
a highly specific sign for left atrial enlargement
(LAE). Amplitude of i-PV1 >1.5 mm is an estab-
lished ECG criterion for RAE. The most commonly
encountered type of significant-Ptf (s-Ptf) is a fully
negative P-wave morphology in V1.10 Increased Ptf
in emphysema may be due to downward right atrial
position caused by RA displacement, and thus the
common assumption that increased P-tf implies LAE
should be made with caution in patients with emphy-
sema. Therefore, s-Ptf and verticalization of P-
vectors in emphysema might be a more functional
outcome of diaphragmatic depression from severe
emphysema rather than RA strain or RAE. The pre-
sent study was undertaken to evaluate the various
NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810
NJMR│Volume 6│Issue 2│Apr – Jun 2016 Page 182
ECG and echocardiographic abnormalities in pa-
tients with stable COPD and to correlate ECG ab-
normalities with echocardiography findings. The ob-
jective was to know the influence of COPD on ECG
changes by comparing the same with echocardio-
graphic findings with an emphasis on P-wave ab-
normalities.
METHODOLOGY
Current study was conducted in the department of
pulmonary medicine, IGMC, Shimla from July 2014
to June 2015. It was an observational prospective
study conducted after prior approval from the ethical
committee. We evaluated 77 consecutive patients
with stable COPD who attended the outpatient de-
partment (OPD) of pulmonary medicine, IGMC
Shimla from various places in Himachal Pradesh. All
subjects were included in study after obtaining in-
formed written consent. Non-COPD cases like
bronchial asthma, pulmonary tubercuosis, lung can-
cer, interstitial lung disease and bronchiectasis; cases
with known co-morbidities like cardiac disease, hy-
pertension, and diabetes mellitus and patient not
willing to give informed consent were excluded.The
selected patients were subjected to detailed history
and thorough clinical examination. We obtained
chest radiography, spirometry, ECG of all subjects
under study. Echocardiography was obtained in 66
patients. Eleven patients failed to get their echocar-
diography done. Preand postbronchodilator spirome-
try was performed as per ATS/ERS recommenda-
tions11 using a spirometer (Spirolab 11) in all subjects
to assess the severity of airflow limitation as per
GOLD guidelines [Table 1].1
A single channel 12-Lead ECG machine (BPL-
CARDIART 6108T) was used to record electrocar-
diographic characteristics. The ECG is recorded on
to standard paper travelling at a rate of 25mm/s. The
paper is divided into large squares, each measuring
5mm wide and equivalent to 0.2 s. Each large square
is five small squares in width, and each small square
is 1 mm wide and equivalent to 0.04s. The electrical
activity detected by the ECG machine is measured in
millivolts. Machines are calibrated so that a signal
with amplitude of 1mV moves the recording stylus
vertically 1cm. throughout this text, the amplitude of
waveforms will be expressed as: 0.1 mV =1mm
=1small square. P-pulmonale is a tall and peaked p-
wave in standard lead II, III and AVF. P-wave height
in lead II will be ≥2.5mm. PWAV is diagnosed by P-
wave amplitude in lead III greater than its amplitude
in lead I or a negative P-wave in aVL. Significant Ptf
is a fully negative P-wave morphology in V1or calcu-
lated by multiplying the duration of the terminal neg-
ative phase of P-wave in V1 (in milliseconds) by its
depth in millimeters. Ptf magnitude of ≥40 mm.ms,
along with the presence of IAB (P-wave duration
>110 ms), is considered a highly specific sign for left
atrial enlargement (LAE). Amplitude of i-PV1 >1.5
mm is an established ECG criterion for RAE. 10
A conventional echocardiography was performed us-
ing “iE33 xMATRIX “ Doppler echocardiography
system and parameters like Pulmonary hypertension,
right atrial enlargement, left atrial enlargement, struc-
tural and functional abnormalities of right and left
ventricles were noted in relation to ECG changes.
Observations and results were statistically compared
and analysed on their mutual relations using SPSS20
software. Chi-Square Test is applied to check the in-
dependence of variables. Chi-Square Test for inde-
pendence is applied when we have two categorical
variables (e.g. heart rate and severity) from a single
population. It is used to determine whether there is a
significant association between the two variables. We
compared ECG changes with gender, age group, du-
ration of illness, mMRC grades, GOLD stages,
smoking status, SI, biomass exposure and BMI. P-
value of less than 0.05 was considered statistically
significant.
RESULTS
We studied the ECG characteristics in all (77) pa-
tients and echocardiography pattern in 66 patients.
ECG and echocardiography findings were compared
with gender, age group, duration of illness, severity
of obstruction (GOLD), smoking status, smoking-
index (SI) and biomass exposure. We also compared
ECG findings with corresponding echocardiography
findings.
Table 1: COPD severity groups by GOLD crite-
ria (Patients with FEV1/FVC ratio less than 0.7)
GOLD 1
Mild
FEV
1
≥ 80%
GOLD 2
Moderate
50% ≥ FEV
1
≤80%
GOLD 3
Severe
30% ≥ FEV
1
≤50%
GOLD 4
Very Severe
FEV
1
<30%
The baseline characteristics of study population with
their number and percentage are shown in [Table 2].
More number of patients(46.6%) were in the age
group of 60 to 69 years. The mean age of the pa-
tients was 64.46 years. Male constituted majority of
our study population. There were 58(75.3%) male
and 19(24.7%) female with a male: female ratio of
3:1. Study population included patients from various
places in and around Shimla and other districts of the
state.
Though the duration of illness was varied from less
than one year to more than 20 years, majority of the
patients i.e., 66(86%) had illness for 1 to 10 years.
Sixty seven (87%) of them were smokers.
NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810
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Table 2: Baseline characteristics of the all study
population compared to Patients with P-wave
axis verticalisation
Characteristics
Study Popula-
ti
on (%) (n=77)
Patients with P-
wave axis verti
calisation(n=59)
Age in years
Mean=64.46
40-49
5 (6.5)
3
50-59
12 (15.6)
9
60-69
36 (46.6)
26
70-79
22 (28.6)
20
80-89
2 (2.7)
1
Gender
Male
58 (75.3)
48
Female
19 (24.7)
11
Duration of Illness in Years
<1
4 (5.2)
3
01 to 05
49 (63.6)
40
06 to 10
17 (22)
10
11 to 15
4 (5.2)
4
16 to 20
2 (2.7)
1
>20
1 (1.3)
1
mMRC grades
Grade0
0 (0)
0
Grade1
35 (45.5)
24
Grade2
36 (46.8)
29
Grade3
6 (7.7)
6
Grade4
0 (0)
0
Smoking status
Never Smoker
10 (13)
6
Ex Smoker
41 (53.2)
29
Current
26 (33.8)
24
Smoking Index
Nil
10 (13)
6
<100
8 (10.3)
8
100-300
20 (26)
17
>300
39 (50.7)
28
Biomass exposure:
Present
42 (54.5)
29
Absent
35 (45.5)
30
BMI Range (kg/m2):
Below normal: <18
31 (40.2)
24
NormalBMI:18-22.9
26 (33.8)
19
Overweight:23.0-24.9
10 (13)
8
Obesity: >25
10 (13)
8
Avg: 14.6-30.4(16.537)
Severity(GOLD)
Normal study
8 (10.4)
4
Mild obstruction
11 (14.3)
9
Moderate obstruction
26 (33.7)
20
Severe obstruction
14 (18.2)
11
Very severe obstruc-
tion
18 (23.4)
15
Beedi smokers were more prevalent than cigarette
smokers. Nearly half of the smokers i.e., 34(44.2%)
were heavy smokers with a smoking index of >300.
Majority of patients were having rural background
and biomass exposure was present in significant
number of patients (54.5%).
Table 3: ECG Characteristics of the study popu-
lation
ECG Characteristics(n=77)
No. (%)
Heart rate/min: (mean: 107.2)
<60
5 (6.5)
60 to 100
64 (83.1)
>100
8 (10.4)
Rhythm
Regular
73 (94.8)
Irregular
4 (5.2)
Axis
Normal
44 (57.1)
Right
18 (23.4)
Left
13 (16.9)
North west
2 (2.6)
P- pulmonale:
24 (31.2)
Ptf-V
1
(significant)
3 (3.9)
P-wave axis verticalisation(PWAV)
59 (76.6)
-ve P-wave in V
1
20 (26)
P- mitrale
18 (31.2)
QTc interval
Normal
37 (48)
Borderline
25 (32.5)
Prolonged
15 (19.5)
Poor R-wave progression(PRWP)
23 (29.9)
Left bundle branch block(LBBB)
5 (6.5)
Left ventricular hypertrophy(LVH)
5 (6.5)
Right bundle branch block (RBBB)
2 (2.6)
Right ventricular hypertrophy(RVH)
8 (10.4)
Exposure to biomass fuel was more prevalent in fe-
male (89.5%) and a major contributor in the devel-
opment of COPD among female particularly in rural
areas. All of them had breathlessness as their primary
symptom which was graded on the basis of mMRC
(modified medical research council) classification.
Most of the patients i.e. 71(92.3%) had mMRC grade
1 to 2 dyspnoea because we included only patients
with stable COPD. The average BMI was 16.5kg/m2
which is below normal. COPD patients were catego-
rised into mild, moderate, severe and very severe
groups as per GOLD criteria based on post-
bronchodilator spirometry. Majority of patients
33.7% had moderate obstruction, whereas 23.4% pa-
tients had very severe obstruction. Severe obstruc-
tion and mild obstruction were seen in 14(18.2%)
and 11(14.3%) patients respectively. Spirometric
study was normal in 8 (10.4%) patients.
The ECG characteristics of the study population,
with their number and percentage are shown in [Ta-
ble 3]. Most of the patients (64) had a heart rate vary-
ing from 60 to 100 per minute with a mean of
107.2/min. It was observed that age, duration of ill-
ness, and mMRC grading had a relation with the
heart rate which was statistically significant. Majority
of patients had regular rhythm with only 3(3.9%) pa-
tients having an irregular rhythm. More than half
(57.1%) of the patients had normal axis, 18(23.4%)
patients had right axis deviation (RAD) and
13(16.9%) had left axis. Only 2(2.6%) patients had an
NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810
NJMR│Volume 6│Issue 2│Apr – Jun 2016 Page 184
axis in the north western region. PWAV was ob-
served in 59(76.6%) patients. Patients with PWAV
was compared with various groups, [Table 2] sum-
marises the same with their number and P-values.
The frequency among male was significantly higher
than female population in the study with 48 male and
11 female. The difference was statistically significant
with P-value of 0.026. Other groups showed no sta-
tistically significant relation with PWAV.
Table 4: Echocardiography findings in the study
population
Echo findings(n=66)
No. (%)
Left atrial enlargement (LAE)
2 (3.0)
Left ventricular enlargement (LVE)
5 (7.6)
Right atrial enlargement (RAE)
21 (30.9)
Right ventricular enlargement (RVE)
23 (34.8)
Left ventricular diastolic dysfunction (LVDD)
52 (76.4)
Tricuspid regurgitation (TR)
46 (70.5)
Pulmonary hypertension (PH)
(TR Gradient >30)
32 (56.0)
Right ventricular dysfunction (RVD)
3 (4.5)
Twenty (26%) patients showed negative P-wave in
V1. Ptf-V1 was measured in patients with positive P-
wave in V1. It was significant only in 3(3.9%) pa-
tients. Only one patient had absent P-wave i.e., atrial
fibrillation. P-pulmonale was seen in 16 (20.8%) pa-
tients. No patient was observed to have Himalayan
P-wave (amplitude >9mm). Poor R-wave progres-
sion was seen in 23(29.9%) patients. Right ventricu-
lar hypertrophy was seen in 8(10.4%) patients. QTc
interval was normal in 48%, borderline in 32.5% and
prolonged in 19.5%.
On echocardiography right atrial enlargement was
present in 30.9% patients, right ventricular enlarge-
ment was observed in 34.8%, left ventricular diastolic
dysfunction was present in 76.4%, measurable tri-
cuspid regurgitation was observed in 70.5% patients,
pulmonary hypertension was present in 56% pa-
tients. Right ventricular dysfunction, left atrial en-
largement and left ventricular enlargement were not
present in significant number. Echocardiography
findings are summarised in [Table 4].
DISCUSSION
COPD is an important public health problem and a
major cause of morbidity and mortality in both de-
veloped and developing countries. Cardiovascular
co-morbidities are frequently seen in COPD patients
and large studies have shown cardiovascular events
as a leading cause of COPD-related mortality.12-14
Identification of ECG abnormalities may have signif-
icant implications in the management and outcome
of patients with COPD. Though ECG can be used
to screen various cardiac abnormalities, electrical ac-
tivities are often influenced by the COPD changes:5
The voluminous lungs have an insulating effect and
there by diminishing the transmission of electrical
potentials to the registering electrodes. The heart de-
scends to a lower position within the thorax due to
lowering of the diaphragm. This will alter the posi-
tion of the heart relative to the conventional precor-
dial electrode positions. The right ventricle and the
right atrium become compromised due to a reduc-
tion of the pulmonary vascular bed and also due to
chronic hypoxemia. This will result in RVH and dila-
tation as well as RAE.
Echocardiography plays an important role in deter-
mining cardiac changes in relation to COPD and also
to detect subclinical cardiovascular abnormalities.
Various studies have been done on ECG and echo-
cardiographic abnormalities in COPD patients.5,15,16
Our study included a total of 77 stable COPD pa-
tients. Majority of the patients were in the age group
of 60 to 69 year with mean age of 64.46 years. Major-
ity of patients in our study were male with a male to
female ratio of 3:1.PWAV was observed in signifi-
cant number of patients i.e., 59(76.6%) among which
48 were male and 11 were female and the difference
in their number was statistically significant with P-
value of 0.026. The difference may be significant be-
cause there was male predominance in the study
population and ECG findings may be masked in fe-
male because of excess soft tissue over chest com-
pared to male. This finding is also supported by the
results observed in relation to BMI. Though the as-
sociation between BMI and PWAV is not statistically
significant, there is definite inverse relation with
BMI. We know that electrical activities of heart are
better conducted in a lean thin patient than obese
patient because of lack of interference by the fat tis-
sue to the electrical waves. We can also say that em-
physematous changes may be more prevalent in pa-
tients with low BMI.
Chhabra et al.17 reported that PWAV is highly effec-
tive for screening emphysema and degree of vertical-
ization provides a gross quantification of the disease.
The results also showed an inverse correlation of
PWAV with FEV1. Though in our study the relation
of PWAV with FEV1 was not statistically significant
the occurrence was frequent in patients showing ob-
struction than those showing normal study on spi-
rometry, thus supporting the Chhabra et al. reports,
but with the current study being prospective we
could not infer on the effectiveness of PWAV for
screening emphysema.
We know that both significant-Ptf with positive P-
wave and negative P-wave in V1 suggest emphysema
and downward right atrial position caused by down-
ward displacement of the diaphragm10, but 20 (26%)
patients showed negative P-wave in V1 and only 3
(3.9%) patients had significant-Ptf suggesting that
NATIONAL JOURNAL OF MEDICAL RESEARCH print ISSN: 2249 4995│eISSN: 2277 8810
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negative P-wave in V1 is the commonest type of sig-
nificant-Ptf which is consistent with the reports by
Chhabra et al.10
P-pulmonale indicates right atrial enlargement, it was
seen in 24 (31.2%) patients and echocardiography
revealed right atrial enlargement in 21patients which
is a comparable number. ECG showed P-mitrale in a
total of 18 (23.4%) patients, but only one out of 18
showed left atrial enlargement on echocardiography
giving an inference that P-mitrale is nonspecific for
left atrial enlargement or overload particularly in
COPD patients. Similarly Ishikawa et al.18in their
study concluded that twinned peaked P-wave or
pseudo P-mitrale is diagnostically non-specific and its
mere existence cannot imply the existence of left
atrial overload. So P-pulmonale may be a reliable in-
dicator of right atrial enlargement where as presence
of P-mitrale is not conclusive of left atrial enlarge-
ment in COPD patients.
Thus change in ECG characteristics in COPD pa-
tients should be meticulously studied and compared
with echocardiography findings as the ECG changes
may be due to change in structure of the lung and
position of the heart due to COPD rather than cardi-
ac abnormality alone.
CONCLUSION
Cardiovascular co-morbidities are seen frequently in
COPD patients and have important prognostic im-
plication. Though not specific, ECG may reveal var-
ious functional and structural abnormalities of the
heart in relation to COPD. P-wave axis verticalisa-
tion, negative P-wave in V1, significant-Ptf and P-
pulmonale are the P-wave abnormalities frequently
encountered in COPD patients. Though P-wave axis
verticalisation, significant-Ptf, P-mitrale all suggestive
of change in structure of the lung and position of the
heart due to COPD, P-wave axis verticalisation may
be the most commonly seen P-wave abnormality
among the three. Negative P-wave in V1 is the fre-
quently seen type of significant-Ptf. P- pulmonale
may be suggestive of right atrial enlargement but
presence of P-mitrale is not conclusive of left atrial
overload particularly in patients of COPD. Echocar-
diography should be done routinely in all patients of
COPD to confirm ECG findings and to diagnose
pulmonary hypertension, cor-pulmonale and other
subclinical cardiovascular co-morbidities like left
ventricular diastolic dysfunction.
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