Electrocardiogram in Pneumonia

Paul D. Stein, MDa,c,*, Fadi Matta, MDa,c, Maan Ekkah, MDd, Tarek Saleh, MDe,
Muhammad Janjua, MDe, Yash R. Patel, MD, MPHb, and Helmi Khadra, BSe
Findings on electrocardiogram may hint that pulmonary embolism (PE) is present when
interpreted in the proper context and lead to definitive imaging tests. However, it would be
useful to know if electrocardiographic (ECG) abnormalities also occur in patients with
pneumonia and whether these are similar to ECG changes with PE. The purpose of this
investigation was to determine ECG findings in patients with pneumonia. We retrospec-
tively evaluated 62 adults discharged with a diagnosis of pneumonia who had no previous
cardiopulmonary disease and had electrocardiogram obtained during hospitalization. The
most prevalent ECG abnormality, other than sinus tachycardia, was minor nonspecific
ST-segment or T-wave changes occurring in 13 of 62 (21%). Right atrial enlargement
occurred in 4 of 62 (6.5%). QRS abnormalities were observed in 24 of 62 (39%). Right-axis
deviation and S1S2S3 were the most prevalent QRS abnormalities, which occurred in 6 of
62 (9.7%). Complete right bundle branch block and S1Q3T3 pattern occurred in 3 of 62
(4.8%). ECG abnormalities that were not present within 1 month previously or abnormal-
ities that disappeared within 1 month included left-axis deviation, right-axis deviation,
right atrial enlargement, right ventricular hypertrophy, S1S2S3, S1Q3T3, low-voltage QRS
complexes, and nonspecific ST-segment or T-wave abnormalities. In conclusion, electro-
cardiogram in patients with pneumonia often shows QRS abnormalities or nonspecific
ST-segment or T-wave changes. ECG findings are similar to ECG abnormalities in PE and
electrocardiogram cannot assist in the differential diagnosis. 2012 Elsevier Inc. All
rights reserved. (Am J Cardiol 2012;110:1836 1840)

The clinical importance of electrocardiogram in pneu- Included patients were adults (18 years old) discharged
monia relates to the differential diagnosis of pneumonia and with a diagnosis of pneumonia who had an electrocardio-
pulmonary embolism (PE). Findings on electrocardiogram gram obtained during that hospitalization. All patients had
may hint that PE is present when interpreted in the proper chest x-ray showing a pulmonary parenchymal abnormality
context and lead to definitive imaging tests. However, it and all were treated with antibiotics. None received thera-
would be useful to know if electrocardiographic (ECG) peutic doses of anticoagulants. Excluded patients were
abnormalities also occur in patients with pneumonia and those with previous or current illness of coronary heart
whether they are similar to ECG changes with PE. The role disease, cardiomyopathy, myocarditis, valvular heart dis-
of electrocardiogram in pneumonia has been sparsely stud- ease, hypertension, chronic obstructive pulmonary disease,
ied.1,2 Therefore, the purpose of this investigation was to emphysema, chronic interstitial fibrosis, chronic bronchial
determine ECG findings in patients with pneumonia. asthma, or PE. Patients with previous atrial fibrillation were
also excluded as were patients who previously showed ECG
Methods abnormalities on admission for pneumonia.
Hospitalized patients with a discharge diagnosis of pneu- Electrocardiograms were read by the principal investiga-
monia from January 2007 to December 2011 were identified tor (P.D.S.) according to criteria listed in Table 1.35
by International Classification of Diseases, Ninth Edition,
Clinical Modification codes 480 to 488. Medical records of Results
these patients were reviewed. This investigation was ap-
proved by the institutional review boards of the participat- From January 2007 to December 2011, 2,593 patients
ing hospitals (St. Mary Mercy Hospital, Livonia, Michigan; had a discharge diagnosis of pneumonia. Of these, 2,487
St. Joseph Mercy Oakland Hospital, Pontiac, Michigan). had previous cardiopulmonary disease or had no electrocar-
diogram obtained during hospitalization. Of 106 patients
with a discharge diagnosis of pneumonia and no previous
Departments of aResearch and bInternal Medicine, St. Mary Mercy cardiopulmonary disease who had an electrocardiogram,
Hospital, Livonia, Michigan; cDepartment of Osteopathic Medical Special- detailed review suggested that in 21 patients pneumonia
ties, Michigan State University College of Osteopathic Medicine, East may not have been present. In 23 patients, previous elec-
Lansing, Michigan; dDepartment of Internal Medicine, Michigan State
trocardiograms showed 1 abnormality during hospitaliza-
University, East Lansing, Michigan; eDepartment of Internal Medicine, St.
Joseph Mercy Oakland Hospital, Pontiac, Michigan. Manuscript received
tion for pneumonia; therefore, these patients were excluded.
July 13, 2012; revised manuscript received and accepted August 1, 2012. Therefore, the sample consisted of 62 patients with pneu-
*Corresponding author: Tel: 734-655-2753; fax: 734-655-8425. monia, no previous cardiopulmonary disease, and elec-
E-mail address: steinp@trinity-health.org (P.D. Stein). trocardiograms with findings not known to be present

0002-9149/12/$ see front matter 2012 Elsevier Inc. All rights reserved. www.ajconline.org
http://dx.doi.org/10.1016/j.amjcard.2012.08.019
 Miscellaneous/Electrocardiogram in Pneumonia 1837

Table 1 Table 3
Criteria for electrocardiographic abnormalities Electrographic findings in 62 patients with pneumonia and no previous
cardiopulmonary disease
Right atrial P wave 0.25 mV (2.5 mm) in extremity leads
enlargement or 0.15 mV in lead V1 Electrocardiographic Finding
Right-axis deviation Mean frontal plane QRS electrical axis 90
Normal electrocardiogram 13 (21%)
Left-axis deviation Mean frontal plane QRS axis equal or leftward of
Rhythm disturbances 40 (65%)
30
Sinus tachycardia 33 (53%)
S1S2S3 pattern S waves in leads I, II, and III 0.15 mV (1.5
Atrial fibrillation 3 (4.8%)
mm) in each lead
Atrial premature contractions 4 (6.5%)
S1Q3T3 pattern S wave in lead I and Q wave in lead III 0.15
Ventricular premature contractions 5 (8.1%)
mV (1.5 mm) with inversion of T wave in lead
Atrioventricular conduction abnormalities
III
First-degree atrioventricular block 2 (3.2%)
Clockwise rotation Shift in transition zone (R S) in precordial
P wave
leads. Usually a shift to the lead V4 position or
Right atrial enlargement 4 (6.5%)
further leftward is considered clockwise
QRS abnormalities 24 (39%)
rotation. For this study, a shift in the transition
Right-axis deviation 6 (9.7%)
zone to lead V5 was analyzed to avoid
Left-axis deviation 4 (6.5%)
problems of interpretation that may occur with
S1S2S3 6 (9.7%)
minor errors of precordial electrode position.
S1Q3T3 3 (4.8%)
Incomplete right QRS duration 0.100.11 second and terminal
Complete right bundle branch block 3 (4.8%)
bundle branch QRS forces directed rightward and anteriorly
Right ventricular hypertrophy 1 (1.6%)
block causing S wave in lead I and R wave in lead
Possible old infarction* 1 (1.6%)
V1
Low voltage (frontal plane) 2 (3.2%)
Complete right QRS duration 0.12 second with terminal QRS
Left ventricular hypertrophy 1 (1.6%)
bundle branch forces directed rightward and anteriorly
Left bundle branch block 1 (1.6%)
block causing S wave in lead I and R wave in lead
Primary ST-segment and/or T-wave abnormalities 13 (21%)
V1
ST-segment depression 2 (3.2%)
Left bundle branch QRS 0.12 second with neither q nor S wave in
T-wave flattening or inversion 4 (6.5%)
block lead I, aVL, or V6 and notched R in these
ST-segment and T-wave changes 7 (11%)
leads
Right ventricular R wave in lead V1 0.5 mV (5 mm) or R/S ratio * Q waves disappeared the next day.
hypertrophy in lead V1 1
Left ventricular R wave in lead aVL 11 mm, or R wave in Table 4
enlargement leads V4, V5, V6 26 mm, or R wave in lead New electrographic findings in six patients with pneumonia who had
V5 or V6 plus S wave in lead V1 35 mm previous electrocardiograms within one month
Low voltage QRS Overall QRS 0.5 mV (5 mm) in all limb leads
Electrocardiographic Finding New Within 1 Month*
complexes
ST-segment ST-segment depression 0.05 mV (0.5 mm) in Atrial premature complexes 1
depression any lead except aVR Ventricular premature complexes 1
T-wave inversion or Present if occurred in any lead except lead aVL, Right atrial enlargement 2
flattening III, aVR, or V1 Right ventricular hypertrophy 1
Left-axis deviation 1
S1S2S3 2
S1Q3T3 1
Low voltage (frontal plane) 1
Table 2
Demographic and clinical findings in 62 patients with pneumonia and no * One patient developed findings 12 hours after admission with a normal
previous cardiopulmonary disease electrocardiogram.

Variable
previously. Demographic and clinical findings are listed
Age (years), mean SD 56 20 in Table 2.
Women 35 (57%) Electrocardiogram was abnormal in 49 of 62 patients
White 49 (79%)
(79%) with pneumonia (Table 3). The most prevalent ECG
Black 10 (16%)
Cough 44 (71%)
abnormality, other than sinus tachycardia, was minor non-
Productive cough 30 (48%) specific ST-segment and/or T-wave changes, occurring in
Leukocytosis 33 (53%) 13 of 62 (21%). At least 1 QRS abnormality occurred in 24
Fever 35 (56%) of 62 (39%). Right-axis deviation and S1S2S3 were the most
Rales 26 (42%) prevalent QRS abnormalities, which occurred in 6 of 62
Sputum culture positive* 19 (31%) (9.7%). Right atrial enlargement occurred in 4 of 62 (6.5%).
Ventilator dependent 4 (6.5%) Complete right bundle branch block and S1Q3T3 pattern
Died 4 (6.5%) occurred in 3 of 62 (4.8%).
* Staphylococcus species in 5, mixed flora in 4, Streptococcus species in Six patients had previous electrocardiogram within 1
2, Pseudomonas species in 2, fungus in 2, Haemophilus influenza in 1, month that did not show any of the abnormalities shown
Legionella species in 1, Serratia and Enterococcus species in 1, and during hospitalization (Table 4). New findings included
atypical Mycoplasma species in 1. S1S2S3, S1Q3T3, low-voltage QRS complexes, left-axis de-
1838 The American Journal of Cardiology (www.ajconline.org)

Figure 1. (Top) Admission electrocardiogram in a 29-year-old man is normal except for sinus tachycardia (rate 105/min). (Bottom) Electrocardiogram in the
same patient 12 hours after admission shows right atrial enlargement, S1S2S3, left-axis deviation (superior axis), and right ventricular hypertrophy.

Table 5 Discussion
Electrographic findings that disappeared within one month in 19 patients
with pneumonia Minor nonspecific ST-segment or T-wave changes were
Electrocardiographic Finding 1-Month Follow-Up the most prevalent ECG abnormalities other than sinus
tachycardia in patients with pneumonia and no previous
Premature atrial contractions 1 cardiopulmonary disease. ECG abnormalities that were new
Premature ventricular contractions 2
(not present within 1 month previously) or abnormalities
Right atrial enlargement 1
Right-axis deviation 1
that disappeared within 1 month included left-axis devia-
Right ventricular hypertrophy 1 tion, right-axis deviation, right atrial enlargement, right ven-
S1S2S3 1 tricular hypertrophy, S1S2S3, S1Q3T3, low-voltage QRS
Nonspecific ST-segment or T-wave changes 2 complexes, and nonspecific ST-segment or T-wave abnor-
Possible old myocardial infarction 1 malities.
Previous investigations of the role of electrocardiogram
in pneumonia are sparse and usually old, before 12-lead
viation, right atrial enlargement, and right ventricular hy- electrocardiograms were obtained.1,2 Thompson et al1
pertrophy (Figure 1). showed nonspecific T-wave changes in 37 of 92 patients
Electrocardiograms obtained within 1 month after initial (40%) with pneumococcal pneumonia. Rightward shift of
electrocardiogram during hospitalization in 19 patients the frontal plane axis was observed in 13% and leftward in
showed disappearance of some ECG abnormalities (Table 5 7%.1 Master et al2 showed nonspecific T-wave changes in
and Figures 2 and 3). Among ECG abnormalities that dis- 36% (16 of 45) with pneumonia. Presence of T-wave
appeared were right atrial enlargement, right axis deviation, changes in patients with pneumonia has been suggested to
S1S2S3, and nonspecific ST-segment or T-wave changes. indicate a poor prognosis.2,6
 Miscellaneous/Electrocardiogram in Pneumonia 1839

Figure 2. (Top) Admission electrocardiogram in a 50-year-old man shows right-axis deviation and right ventricular hypertrophy. (Bottom) Electrocardiogram
in the same patient 1 day after admission shows the absence of right-axis deviation and right ventricular hypertrophy.

In patients with pneumonia, new left-axis deviation All ECG changes shown in patients with pneumonia have
and new right-axis deviation were observed. In patients been shown in patients with PE3,7 and the prevalence of most
with PE who had no previous cardiopulmonary disease, ECG changes was comparable in pneumonia and in PE. Al-
new left-axis deviation was more frequent than new though in the appropriate setting ECG abnormalities may sug-
right-axis deviation.7,8 gest the possibility of PE, ECG abnormalities are not specific
Low-voltage frontal plane QRS complexes were shown for PE and cannot assist in the differentiation of PE from
in 9.7% of patients with pneumonia and in 3% to 6% of pneumonia. Conversely, pneumonia cannot be excluded based
patients with PE.2,7 Right ventricular endocardial potential on ECG abnormalities.
is decreased in massive PE, possibly reflecting acute myo- Strengths of this investigation are identification of patients with
cardial stress.9 new findings on electrocardiogram and findings that disappeared
In patients with pneumonia, an electrocardiogram sug- within 1 month. Additional strengths are the exclusion of patients
gesting an old myocardial infarction was shown in 1 patient with previous cardiopulmonary disease (not previously done by
(1.6%). These Q waves disappeared in 1 day. Q waves were others) and the exclusion of patients with known abnormalities on
not accompanied by ST-segment or T-wave changes. Pseu- electrocardiogram before admission.
doinfarction was observed in 3% to 11% of patients with A weakness is that the investigation was retrospective.
acute PE.3,7 Some patients may have had the reported ECG abnormali-
1840 The American Journal of Cardiology (www.ajconline.org)

Figure 3. (Top) Admission electrocardiogram in a 76-year-old woman shows right atrial enlargement. (Bottom) Electrocardiogram in the same patient 1 day
after admission shows absence of right atrial enlargement.

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Heart, 11th Ed. New York: McGraw-Hill, 2004:295324.
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Conditions affecting the left side of the heart. BMJ 2002;324:1264
1267.
Acknowledgment: Muhammad Sadiq, MD, and Joshi 6. Trushinskii ZK, Striuk RI, Krasnololskaia SP. Prognostic significance
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BT, Weg JG. Clinical, laboratory, roentgenographic, and electrocardio-
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1946;31:565579. 8. Lynch RE, Stein PD, Bruce TA. Leftward shift of frontal plane QRS
2. Master AM, Romanoff A, Jaffe H. Electrocardiographic changes in axis as a frequent manifestation of acute pulmonary embolism. Chest
pneumonia. Am Heart J 1931;6:696 709. 1972;61:443 446.
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