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The evolution of electrocardiographic signs of right ventricular overload after balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension.

INTRODUCTION
Balloon pulmonary angioplasty (BPA) is a treatment option for a patient with chronic thromboembolic pulmonary hypertension (CTEPH).


OBJECTIVES
We aimed to investigate the evolution of electrocardiographic (ECG) markers of right ventricular hypertrophy (RVH) after BPA.


PATIENTS AND METHODS
In 41 patients with CTEPH the standard 12-lead ECG was performed before the first BPA session and after completion of treatment.


RESULTS
In the whole study group, the percentage change in the pulmonary vascular resistance (PVR) after BPA correlated with the percentage change in the values of the following ECG parameters (p<0.05): axis of the QRS (rho = 0.530) and T waves (rho = 0.372); P wave in  II (rho = 0.340) and III (rho = 0.430); S wave in V5 (rho = 0.634); R:S ratio in V5 (rho = -0.636); S wave in V6 (rho = 0.508); S wave in  I (rho = 0.496). Then, the above group was divided into two subgroups: group A, defined as a drop in PVR greater than the median value (49%) for the whole studied population, and group B, defined as a drop in PVR below the median value. In group A - T wave axis (p<0.001), P wave in II (p<0.001), S wave in V5 (p<0.001), R:S ratio in V5 (p<0.001) changed significantly after BPA. In group B, despite some hemodynamic and functional improvement, no significant differences on ECG markers of RVH after BPA were found.


CONCLUSIONS
After a hemodynamically effective BPA, a significant improvement in RVH parameters could be observed by ECG.