Abnormal Heart Rhythm More Common in PAH Patients Than Thought, Study Says

In a moderately sized group of patients with pulmonary hypertension (PH), nonsustained ventricular tachycardia (nsVT) occurred more often than previously reported, researchers said, and patients with PH group 1 seemed to be more at risk.

Nonsustained ventricular tachycardia is an abnormally rapid ventricular rhythm, usually greater than 100 beats per minute, that stops by itself within 30 seconds. It can cause lightheadedness, dizziness, or, more rarely, syncope (loss of consciousness). The symptoms occur because ventricular tachycardia disrupts the heart’s ability to pump effectively.

Researchers said larger groups need to be assessed to confirm the results reported in the article, “Prognostic Relevance of Nonsustained Ventricular Tachycardia in Patients with Pulmonary Hypertension.” It was published in the journal BioMed Research International.

Patients with PH group 1 (pulmonary arterial hypertension, or PAH) and group 4 (chronic thromboembolic pulmonary hypertension, or CTEPH), were tested for nsVT using the Holter electrocardiogram (ECG) exam. The goal was to assess whether nsVT could help predict their prognosis.

A total of 78 patients were evaluated in the retrospective study: 55 with PAH and 23 with CTEPH. Holter ECG exams showed nsVT in 12 people (eight with PAH and 4 with CTEPH).

“By extending Holter ECG monitoring time up to 72 (hours), the detection rate of patients with nsVT increased. In three patients, nsVT was observed during the first 24 (hours), in seven patients between 24 and 48 (hours), and in two patients between 48 and 72 (hours) of the recording,” the authors wrote.

Among the patients with nsVT, four with PAH died. Right heart failure was named the cause in two patients. Decompensated aortic valve stenosis and sudden cardiac death were cited in the others.

The average time from initial diagnosis to death was 8.4 years in patients without nsVT, and 7.9 years in those with it. The average interval was 8.2 years in PAH patients, and 8.5 years in those with CTEPH.

Patients took six-minute walk tests (6MWT) to assess their exercise capacity, and the average walked distance was 370 meters (patients without nsVT walked 387 meters; those with nsVT, 283 meters).

“In patients with PH, nsVT occurs more often than previously reported, and patients with PH group 1 seem to be more at risk. Because of the moderate sample sizes, the prognostic relevance and risk factors for the development of nsVT in these patients cannot finally be assessed. Studies with a larger number of patients to obtain more information about the prognostic relevance of nsVT and risk factors … for the development of nsVT are necessary,” the team wrote.