Non‐Invasive Beat‐to‐Beat Analysis of Stroke Volume and Digital Pulse Volume in Patients with Complete Heart Block and Artificial Pacing

Abstract

This study presents a beat-to-beat analysis of digital arterial pulse volume (DAPA), left ventricular end-diastolic diameter (LVEDD), and stroke volume (SV) and their correlation to PQ interval in ten patients with complete heart block and artificial cardiac pacing. DAPA was measured by strain-gauge plethysmography and LVEDD/SV by echocardiography. A close relationship was found between SV and DAPA (R = 0.83-0.97) in seven patients, who all drew considerable benefit from atrial contraction as regards SV and DAPA (increase with 35-94%). The optimal PQ interval was calculated to approximately 240 msec for DAPA and 180 msec for LVEDD and SV. It may be concluded that the present study demonstrates a close relationship between beat-to-beat variations of SV measured by echocardiography and plethysmographically recorded digital arterial pulse volume. These variables may be useful in clinical practice for assessing the hemodynamic effect of atrial contribution in patients with various forms of cardiac conduction disturbances. The two methods may, for instance, be useful for screening in order to pick out patients who may benefit from AV synchronous rather than ventricular pacing.