A majority of patients with pulmonary arterial hypertension (PAH) have abnormalities in the lower left chamber of the heart, or left ventricle (LV), according to a new study. These patients tend to be older and to have higher blood pressure in the arteries supplying the lungs when the heart muscle contracts.
PAH is caused by high blood pressure in the arteries that supply blood to the lungs, and the condition is known to cause abnormalities in the right ventricle (RV) of the heart.
The ventricles are the two lower chambers in the heart on the left and right sides. The right ventricle pumps blood to the lungs, and from the lungs the blood returns to the left side of the heart and to the left ventricle. In this study, the goal was to see whether the left ventricle of the heart is also affected in PAH.
Researchers measured diastolic function in the LVs of 128 patients with PAH. Diastolic function is defined as left ventricle relaxation and filling. LV diastolic function was classified as normal with no LV diastolic dysfunction (LVDD 0), impaired relaxation (LVDD 1), and pseudonormal (LVDD 2).
Abnormal LVDD was present in 82 (64%) of the PAH patients studied. The most commonly identified LVDD Doppler pattern was early relaxation abnormality (LVDD 1) in 61 (48%) of the patients. A total of 21 (16%) of all PAH patients showed a pseudonormal pattern (LVDD 2).
Patients with LV abnormalities were older and tended to have a higher pulmonary artery systolic pressure (PASP). Systolic pressure is the blood pressure in the arteries during contraction of the heart muscle (when the heart is pumping blood to the arteries).
“Even though this study was not intended to provide anatomical or mechanistic explanations to explain the development of LVDD in PAH patients, our results not only seem to confirm but also expand our knowledge of LV diastolic function in PAH by identifying impaired relaxation as a common abnormality in these patients,” the authors concluded.
“Additional studies are now required to determine if impaired LV relaxation alters prognosis or is related to change in the symptomatic profile of PAH patients,” they added.