Transient Supine-Induced Advanced Heart Block in an Octogenarian

Abstract

Atrioventricular block (AVB) is a conduction disorder that can lead to significant bradyarrhythmias with resultant hemodynamic compromise and cardiogenic shock. While most cases of positional AVB that occur during erect posture are attributed to neurocardiogenic mechanisms, complete AVB occurring exclusively in the supine position is an exceedingly rare phenomenon. We present a case of an 87-year-old Caribbean Black male who presented with symptomatic supine-induced advanced heart block, which transiently resolved during standing with unremarkable comprehensive investigations and subsequently underwent successful dual-chamber permanent pacemaker implantation. The clinician should be cognizant of assessing positional vital signs with telemetric monitoring in patients presenting with idiopathic bradyarrhythmias and presyncope.

Keywords: advanced heart block; bradyarrhythmias; complete heart block; position-dependent atrioventricular block.

Figure 1.

The patient’s positional 12-lead ECGs. (A) The patient’s ECG when standing illustrating normal sinus rhythm with subtle nonspecific ST-T changes. Some minor motion artifacts were observed (I, aVL). (B) The patient’s ECG when supine demonstrating complete AVB, with an atrial rate of 70 beats per minute and ventricular rate of 36 beats per minute with a borderline-wide QRS complex. AVB, atrioventricular block; ECG, electrocardiogram.