Automatic Optimization of Resting and Exercise Atrioventricular Interval Using a Peak Endocardial Acceleration Sensor: Validation with Doppler Echocardiography and Direct Cardiac Output Measurements

Abstract

LEUNG, S.-K., ET AL.: Automatic Optimization of Resting and Exercise Atrioventricular Interval Using a Peak Endocardial Acceleration Sensor: Validation with Doppler Echocardiography and Direct Cardiac Output Measurements. Peak endocardial acceleration (PEA) measured by an implantable acceleration sensor inside the tip of a pacing lead reflects ventricular filling and myocardial contractility. The contri bution of the plateau phase of PEA as an indicator of optimal ventricular filling, hence of the appropriate atrioventricular interval (AVI) at rest and during exercise, was studied in 12 patients (age 69 ± 6 years) with complete A V block anda PEA sensing DDDR pacemakers (Living 1 Plus, Sorin Biomedica). At a mean resting heart rate of 79 ± 15 beats/min, the mean AVI optimized by PEA versus Doppler echocardiogra phy (echo) were identical (142 ± 37 vs 146 ± 26 ms, P = 0.59). During submaximal exercise at a mean heart rate of 134 ± 6 beats/min, AVI optimized by PEA was 135 ± 37 ms. Cardiac output at rest, measured by the C0 2 rebreathing method, was comparable with AVI determined by echo versus PEA (4.3 ± 2.9 and 3.7 ± 2.4 L/min, respectively), and increased to the same extent (8.0 ± 3.9 vs 8.3 ± 5.2 L/min) during submaximal exercise. In patients with AV block, AVI automatically set by PEA was comparable with AVI manually optimized by Doppler echocardiography and was associated with comparable exercise induced hemodynamic changes. (PACE 2000; 23[Pt. II]:1762-1766) atrioventricular interval, peak endocardial acceleration, Doppler echocardiography, cardiac output

A relative value method for measuring and evaluating cardiac reserve

“…Previous studies on the relationship between the amplitude of the first heart sound (S1) and cardiac contractility offer a way to reconcile the measurements. Animal experiments and invasive and non-invasive clinical trails have shown that there is a very close relationship between the amplitude of the first heart sound (S1) and the cardiac contractility [9-12]. The animal study by Hansen et al [9] showed that changes in the amplitude of the first heart sound are found to correlate closely with changes in the maximum rate of rise of left ventricular pressure (r = 0.9551, P < 0.001) [9].…”

Different Automatic Mode Switching in DDDR Pacemakers

“…28 In a report on patients with a singlelead VDD pacemaker, 9% developed AF over a follow-up of 5.5 years. (28)(29). Thus, the incidence of AF between DDD and VDD appears comparable.…”

“…Although reprogramming to a non-tracking mode (such as DVI, DDI or DDIR) prevents this clinical event, these modes do not provide appropriate AV synchrony if the sinus rate exceeds the programmed lower rate. (26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37) Limitation of the upper tracking rate only partly addresses this problem and may compromise exercise capacity or lead to symptoms from pacemaker Wenckebach behaviour at relatively slow rates. In response to this clinical dilemma, a variety of mode-switching algorithms has been devised that are meant to prevent tracking of pathological atrial tachy-arrhythmias while allowing ventricular pacing that is synchronous with the atrial electrocardiogram during sinus rhythm [17][18][19].…”

Implantable Sensors for Rate Adaptation and Hemodynamic Monitoring

“…31,32 Similar results were obtained in patients tested during electrophysiologic studies using an external system; changes in PEA were linearly related to the RV dp/dt during dobutamine infusion. 33 The algorithm is now automatic. In 13 patients with end-stage heart failure implanted with a DDD-PEA device with a custom lead arrangement, PEA level during RV, LV, and biventricular (BiV) pacing were compared.…”