Preclinical cardiac involvement in phaeochromocytoma: a study with integrated backscatter

It is well known that vascular and cardiac structure may be influenced by circulating neurohormonal factors. Our aim was to study the myocardial wall texture by integrated backscatter (IBS) analysis in patients with phaeochromocytoma (PHEO).

Fourteen patients with PHEO, 15 matched high-normal blood pressure (BP) subjects, 15 mild essential hypertensives and 15 normotensive controls underwent two-dimensional conventional ultrasonography and ultrasonic IBS of the myocardial wall. IBS analysis was performed at both interventricular septum and posterior wall levels. IBS values were expressed in decibels and corrected for the IBS values obtained within the pericardium (C-IBS). The systo-diastolic cyclical variations in IBS (CV-IBS), an index of myocardial contractile performance, were also evaluated.

Patients with PHEO showed C-IBS values comparable to those of hypertensive patients, and significantly higher than those of high-normal BP subjects and controls at both septum and posterior wall levels (P < 0.001 for all). In PHEO patients, CV-IBS was lower than that of normotensive, high-normal BP subjects and hypertensive patients, at both septum and posterior wall levels (P < 0.001 for all). An inverse relationship was found in the PHEO group between 24-h urinary normetanephrine and CV-IBS of both septum (r(2) = -0.29, P < 0.05) and posterior wall (r(2) = -0.46, P < 0.05).

Our results show that patients with PHEO have myocardial remodelling characterized by increased myocardial fibrosis, confirmed by an increase in the overall myocardial backscatter level measured. The observed decrease in the magnitude of CV-IBS suggests an impairment of myocardial contractile performance. These results may provide insights into the role of catecholamines in left ventricular (LV) structure and function in PHEO.