Methods: A total of 48 patients (42 males, 6 females; mean age 29.7±12.5 years, range 15 to 58 years) with PSP were prospectively analyzed between November 2010 and November 2011. Pneumothorax size was calculated using the Rhea method. At least two standard 12-lead ECG were obtained for each patient (after the diagnosis of pneumothorax and prior to drain placement - ECG_pneumothorax, and after a complete re-expansion of the lung was achieved and confirmed radiologically - ECG_re-expanded). P wave measurement, PR distance, QRS distance, QT interval and QT interval corrected for heart rate (QTc) were calculated. Heart rate (bpm), axis deviation measurement and the QRS amplitudes (QRSV1-6) in precordial leads were calculated.

Results: There were 29 cases (60.4%) of left-sided and 19 cases (39.6%) of right-sided pneumothorax. The mean relative volume of pneumothorax was 43.0±21.5%. The most common symptoms included chest pain in 34 patients (70.8%) and dyspnea in 14 patients (29.2%). The pneumothorax duration was ≤24 hours in 30 patients (62.5%) and >24 hours in 18 patients (37.5%). There was a statistically significant difference between before and after the treatment for QT duration, axis deviation, heart rate, QRSV1, QRSV4, QRSV5 and QRSV6 (respectively; p=0.001, p=0.023, p=0.001, p=0.010, p=0.046, p=0.000, p=0.008). A total of seven patients had relevant QRS abnormalities including incomplete right bundle branch block in three patients, ST elevation in two patients and T-wave pointedness in one patient.

Conclusion: Our study results suggest that left and right lung pneumothorax may cause axis variation, which is more pronounced in women, and that voltage increases after drainage in QRSV 4, 5 and 6 leads. In addition, pneumothorax may lead to specific ECG variations such as right bundle branch block and ST variations.