Incidence and clinical relevance of supraventricular tachyarrhythmias in pulmonary hypertension

Background In patients with severe pulmonary hypertension (PH), right ventricular function is a main determinant of clinical stability and outcome. Supraventricular tachyarrhythmias (SVTs) may compromise cardiac function and threaten prognosis in patients with PH, but the incidence and clinical relevance of SVTs in PH and chronic right ventricular failure have not been evaluated. Methods In a 6-year retrospective single-center analysis, 231 consecutive patients followed for pulmonary arterial hypertension, or inoperable chronic thromboembolic PH were studied for SVTs. Analysis included incidence, clinical consequences, treatment, and outcome. Results Thirty-one episodes of SVT were observed in 27 of 231 patients (cumulative incidence 11.7%, annual risk 2.8% per patient), including atrial flutter (n = 15), atrial fibrillation (n = 13), and AV nodal reentry tachycardia (n = 3). Supraventricular tachyarrhythmia onset was almost invariably associated with marked clinical deterioration and right ventricular failure (84% of SVT episodes). Outcome was strongly associated with the type of SVT and restoration of sinus rhythm. During follow-up, cumulative mortality was low (6.3%, follow-up 26 ± 23 months) when sinus rhythm was restored (all cases of AV nodal reentry tachycardia and atrial flutter). In contrast, 9 of 11 patients with sustained atrial fibrillation died from right ventricular failure (cumulative mortality 82%, follow-up 11 ± 8 months). Conclusions In patients with PH, SVTs constitute a relevant problem, often resulting in clinical deterioration. Sustained atrial fibrillation may be associated with a high risk of death from right ventricular failure.