Comparison of baseline non- invasive hemodynamic evaluation among patients with advanced conduction disorders based on high Vs. low peripheral vascular resistance reserve

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Patients with advanced conduction disorders can have various hemodynamic presentation ranging from cardiovascular shock to an excessive hypertension state. The peripheral vascular resistance has an important role in the physiology of compensation mechanisms related to reduced heart rate. We aimed to compare baseline characteristics among patients with advanced conduction disorders based on high versus low peripheral vascular resistance reserve. Methods We performed a non-invasive hemodynamic study using the NicaS system (whole-body bio-impedance monitoring system) in 47 patients who presented with advanced conduction disorder and required pacemaker implantation. Non-invasive hemodynamic parameters including total peripheral resistance index (TPRI) were measured before and after pacemaker implantation. TPRI reserve was defined as the change between the two TPRI measurements. Patients were categorized to have high or low TPRI reserve. We compared baseline characteristics based on high vs. low TPRI reserve. Results There were 27 (56%) patients presented with complete AV block and 21 (44%) with other advanced conduction disorders. The average heart rate at presentation was 38.5±5.3 with cardiac output of 2.5±0.6 and cardiac index of 1.4±0.3. Twenty-three patients were categorized with high TPRI reserve. The mean age of patients with high and low TPRI reserve was 77 ± 11 years and 75 ± 16 years, respectively. The systolic blood pressure at presentation for patients with high TPRI reserve was 176 ± 25 mmHg vs. 156 ± 29 mmHg among patients with low TPRI reserve (p-value=0.016). The diastolic blood pressure was similar among patients having high and low TPRI. High TPRI reserve was not correlated with history of hypertension, lower heart rate, lower cardiac output or cardiac index at presentation. Conclusion High systolic blood pressure at presentation of patients with advanced heart conduction disorders is associated with higher peripheral resistance reserve.