Dear Sirs,
We read with interest the article by Yamamoto et al.,1 regarding the distinct electrocardiographic (ECG) manifestations in a large primary spontaneous right-sided pneumothorax. We concur that physicians’ awareness of possible right-sided pneumothorax associated ECG manifestations remains insufficient and not well reported.1
Yamamoto et al. highlighted multiple distinct ECG manifestations including phasic voltage variation, P-pulmonale and vertical P-wave axis.1 Our case, recently published in the Journal of Electrocardiology,2 also reported similar unique ECG changes, but in a smaller right-sided pneumothorax. We recognised a new vertical P-wave axis, increased P-wave amplitude in the inferior leads (which did not fluctuate on deep inspiration) and ST-elevation in V1–V2. All ECG changes resolved following decompression with an intercostal drain.
The mechanism behind these ECG manifestations is not entirely clear. It has been suggested the right-sided pneumothorax depressed the right hemi-diaphragm causing right atrial stretching, which results in a vertical P-wave axis and increased P-wave amplitude;1 this suggested pathophysiological mechanism appears to be supported by the correlation between diaphragm levels and P-wave axis and amplitude.3 Also, Kataoka et al. speculated the ST-segment elevation is due to the build-up of intrapleural air, shifting the cardiac silhouette and exerting pressure on the coronary vessels resulting in ischaemia.4 Similar to Yamamoto et al., we have not found a vertical P-wave axis being reported in left-sided pneumothoraces. We concur with Yamamoto et al. that this ECG manifestation can, therefore, be considered specific to the right-sided pneumothorax.
ECG manifestations in a large left-sided pneumothorax have been well described, with phasic voltage variation being a specific sign.5,6 Other manifestations include: right QRS axis deviation, low QRS voltage, reduced precordial R-wave voltage, ST-segment elevation and T-wave inversion.7,8 The mechanism causing the ECG changes has been attributed to displacement of the heart around its longitudinal axis; sudden increase in pulmonary vascular resistance resulting in right ventricular dilation; and interference with conduction of electrical signals by retrosternal air mass.9,10
Patients with a primary spontaneous pneumothorax are at risk of severe cardio-pulmonary collapse; thus, early recognition is important. The unique ECG changes described can be useful for physicians in emergency and ward-based settings where ECGs are routinely done on patients with acute chest symptoms and dyspnoea. We, therefore, strongly encourage our medical colleagues to be aware of the reported left and right pneumothorax-associated ECG manifestations.
Conflicts of interest
None declared.
Funding
None.
References
1. Yamamoto H, Satomi K, Aizawa Y. Electrocardiographic manifestations in a large right-sided pneumothorax. BMC Pulm Med 2021;21:101. https://doi.org/10.1186/s12890-021-01470-1
2. Sooltan I, Khan S, Dzhakhangirli F, Bulugahapitiya S, Khalid T. Electrocardiographic changes in a right-sided pneumothorax. J Electrocardiol 2023;80:7–10. https://doi.org/10.1016/j.jelectrocard.2023.04.005
3. Shah NS, Koller SM, Janower ML, Spodick DH. Diaphragm levels as determinants of P axis in restrictive vs obstructive pulmonary disease. Chest 1995;107:697–700. https://doi.org/10.1378/chest.107.3.697
4. Kataoka E, Kimura M, Iwai T, Sawada T. ST-segment elevation mimicking inferior wall myocardial infarction caused by right tension pneumothorax. Circ J 2022;86:1590. https://doi.org/10.1253/circj.CJ-22-0135
5. Hallengren B. Phasic voltage alternation in spontaneous left-sided pneumothorax. Acta Med Scand 1979;205:143–4. https://doi.org/10.1111/j.0954-6820.1979.tb06020.x
6. Kurisu S, Inoue I, Kawagoe T. Phasic voltage variation on electrocardiogram in pneumothorax. Intern Med 2008;47:471–2. https://doi.org/10.2169/internalmedicine.47.0785
7. Kozelj M, Rakovec P, Sok M. Unusual ECG variations in left-sided pneumothorax. J Electrocardiol 1997;30:109–11. https://doi.org/10.1016/S0022-0736(97)80018-0
8. Karaüzüm K, Gökçek MD, Kalaş B, Karaüzüm İ, Ural E. A transient inferolateral ST-segment elevation on the electrocardiogram due to an iatrogenic left-sided pneumothorax after an urgent tracheostomy in a patient with metastatic hypopharynx cancer. Turk Kardiyol Dern Ars 2023;51:72–5. https://doi.org/10.5543/tkda.2022.28589
9. Klin B, Gueta I, Bibi H, Baram S, Abu-Kishk I. Electrocardiographic changes in young patients with spontaneous pneumothorax: a retrospective study. Medicine (Baltimore) 2021;100:e26793. https://doi.org/10.1097/MD.0000000000026793
10. Walston A, Brewer DL, Kitchens CS, Krook JE. The electrocardiographic manifestations of spontaneous left pneumothorax. Ann Intern Med 1974;80:375–9. https://doi.org/10.7326/0003-4819-80-3-375
