Pathophysiology, incidence, management, and consequences of cardiac arrhythmia in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Abstract

Arrhythmias are increasingly recognized as serious, end-stage complications of pre-capillary pulmonary hypertension, including pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Although arrhythmias contribute to symptoms, morbidity, in-hospital mortality, and possibly sudden death in PAH/CTEPH, there remains a paucity of epidemiologic, pathophysiologic, and outcome data to guide management of these patients. This review summarizes the most current evidence on the topic: from the molecular mechanisms driving arrhythmia in the hypertrophied or failing right heart, to the clinical aspects of epidemiology, diagnosis, and management.

Chronic Thromboembolic Pulmonary Hypertension – What Have We Learned From Large Animal Models

“…Three countries assessed the CTEPH incidence through nationwide registries. In the United Kingdom the CTEPH incidence was 1.75 per million (26), in Spain it was 0.9 per million adults (12) and in Germany it was 5.7 per million adults (27). Between ∼300 and 400 patients were newly diagnosed with CTEPH per year in France and Germany (28,29).…”

“…Ventricular arrhythmias such as ventricular tachycardia (VT) or ventricular fibrillation (VF) have been demonstrated only in about 8% of patients with PAH and sudden cardiac death (SCD) (117). Due to the pathophysiologic alterations in PAH and the observation of VF and VT in a rat model of PAH (118,119) one would expect a higher incidence of VT/VF in PAH patients potentially indicating difficulties in diagnosing ventricular arrhythmias due to a lack of permanent ECG monitoring (e.g., implantable loop recorders) in such patients (12). Even more frequent than specific arrhythmias are ECG abnormalities in PAH patients.…”

“…The degree of RV structural remodeling and functional adaptability have been demonstrated to be important determinants of functional capacity and survival in patients with CTEPH (8)(9)(10). In addition to RV remodeling, CTEPH is a risk factor for development of arrhythmias, especially atrial fibrillation (AF), which adds to the morbidity and mortality of patients with CTEPH (11,12).…”

Atrial arrhythmias in chronic lung disease‐associated pulmonary hypertension

“…Changes of myocardial ion channel distribution and activation cause electrical remodeling of the right atrium, which further increase arrhythmogenic vulnerability. 12 Atrial remodeling potentiates ectopic or reentrant activity and can precipitate AAs. 13 Remodeling further increases the arrhythmogenic substrate and ectopic activity, which in itself can function as a trigger for reentrant activity that leads to atrial arrythmias.…”

“…15 Slowing of both atrial conduction and atrial activation time are essential for AF activation and maintenance. 12 Changes in sarcolemmal sodium cannels, gap junction channels, or tissue structure cause slowing of atrial conduction. Fibrotic areas contribute to areas of reduced tissue voltage and regionals of electrical silence which promote areas of ectopic activity.…”