Electrocardiographic manifestations in a large right-sided pneumothorax

Abstract

Background: Pneumothorax is an extrapulmonary air accumulation within the pleural space between the lung and chest wall. Once pneumothorax acquires tension physiology, it turns into a potentially lethal condition requiring prompt surgical intervention. Common symptoms are chest pain and dyspnea; hence an electrocardiogram (ECG) is often performed in emergent settings. However, early diagnosis of pneumothorax remains challenging since chest pain and dyspnea are common symptomatology in various life-threatening emergencies, often leading to overlooked or delayed diagnosis. While the majority of left-sided pneumothorax-related ECG abnormalities have been reported, right-sided pneumothorax-related ECG abnormalities remain elucidated.

Case presentation: A 51-year-old man presented to the emergency department with acute-onset chest pain and dyspnea. Upon initial examination, the patient had a blood pressure of 98/68 mmHg, tachycardia of 100 beats/min, tachypnea of 28 breaths/min, and oxygen saturation of 94% on ambient air. Chest auscultation revealed decreased breath sounds on the right side. ECG revealed sinus tachycardia, phasic voltage variation of QRS complexes in V4-6, P-pulmonale, and vertical P-wave axis. Chest radiographs and computed tomography (CT) scans confirmed a large right-sided pneumothorax. The patient's symptoms, all the ECG abnormalities, and increased heart rate on the initial presentation resolved following an emergent tube thoracostomy. Moreover, we found that these ECG abnormalities consisted of two independent factors: respiratory components and the diaphragm level. Besides, CT scans demonstrated the large bullae with a maximum diameter of 46 × 49 mm in the right lung apex. Finally, the patient showed complete recovery with a thoracoscopic bullectomy.

Conclusions: Herein, we describe a case of a large right-sided primary spontaneous pneumothorax with characteristic ECG findings that resolved following re-expansion of the lung. Our case may shed new light on the mechanisms underlying ECG abnormalities associated with a large right-sided pneumothorax. Moreover, ECG manifestations may provide useful information to suspect a large pneumothorax or tension pneumothorax in emergent settings where ECGs are performed on patients with acute chest pain and dyspnea.

Keywords: Chest pain; Electrocardiogram; P-pulmonale; Phasic voltage variation; Right-sided pneumothorax; Vertical P-wave axis.

Fig. 1

Electrocardiogram. Electrocardiogram reveals sinus tachycardia of 100 beats/min and prominent phasic voltage variation of QRS complexes in precordial leads (V4–6). The P-waves’ abnormally high amplitude (arrows, maximum 3.0 mm in voltage, reference: < 2.5 mm) in the inferior leads, and vertical P-wave axis are observed. The P-wave inversion in aVL (arrowhead) is visible

Fig. 2

Initial chest radiographs and computed tomography scans (a, c, and d: during inspiration, b: during expiration). a Chest radiographs reveal a huge right-sided pneumothorax during inspiration. The absence of lung markings peripheral to the thin white visceral pleural line (white arrowheads) can be noted. b During expiration, increased intercostal space and a pronounced leftward mediastinal shift (arrows) are recognized. The hemidiaphragm on the right side remains quite depressed. c, d Chest computed tomography scans reveal a huge right-sided pneumothorax during inspiration. The extracardiac compression of the right atrial free wall result in a straightened cardiac border (yellow arrowheads). RA right atrium, RV right ventricle

Fig. 3

Follow-up chest radiographs and computed tomography scans of the post-tube thoracostomy (a, c, d: during inspiration, b: during expiration). a–d Follow-up chest radiographs and computed tomography scans reveal the resolution of pneumothorax. The resolution of right atrial collapse can be noted. RA right atrium, RV right ventricle

Fig. 4

A follow-up electrocardiogram (ECG) following the tube thoracostomy. A follow-up ECG after the tube thoracostomy revealed normalization of increased heart rate and the resolution of all the ECG abnormalities recognized on initial ECG