An Unexpected Cause of Severe Hypertension and Bradycardia: The Role of Hemodynamic Assessment by Echocardiography.

Severe hypertension has numerous etiologies. When accompanied by bradycardia, the spectrum of differential diagnoses is greatly narrowed and is commonly seen in patients with increased intracranial pressure. However, other etiologies such as bradycardia-induced hypertension are rarely mentioned. Here we report the case of a 73-year-old woman presenting with symptoms of heart failure, severe hypertension, and bradycardia with a 2:1 atrioventricular block. Echocardiography demonstrated increased left ventricular filling secondary to bradycardia and prolonged diastole, leading to greater ventricular stretch, increased contractile force and greater stroke volume (Frank-Starling mechanism), which subsequently caused elevated systolic blood pressure (BP), low diastolic BP and a wide pulse pressure. Treating the bradycardia by pacing led to an immediate and substantial BP reduction, although complete BP normalization had a slower time course and was probably due to the concomitant effect of the antihypertensive treatment initiation. This pathophysiological mechanism has received little attention in the literature. Further, stimulation of sympathetic afferents located in the heart by distension of the cardiac walls as well as the role of vagally innervated cardiopulmonary receptors due to the increased pressure in the heart and the pulmonary artery should also be kept in mind as alternative hypotheses.