Hypertensive vs normotensive blood pressure response to advanced conduction disorders -comparison of baseline non-invasive hemodynamic evaluation.

Aims: Patients with advanced conduction disorders exhibit diverse hemodynamic profiles, from cardiogenic shock to severe hypertension. Peripheral vascular resistance (PVR) significantly contributes to compensatory mechanisms during bradycardia. This study aimed to assess the hemodynamic responses of patients presenting with high-degree atrioventricular (AV) block.

Methods and results: We retrospectively analyzed 261 consecutive patients with advanced conduction disorders who underwent pacemaker implantation from October 2020 to December 2022. Patients were classified into three groups: normotensive (<160 mmHg), hypertensive (≥160 mmHg), and unstable (requiring emergent temporary pacing). Additionally, 73 stable patients underwent non-invasive hemodynamic assessment. Of 261 patients, 99 (37.9%) were normotensive, 118 (45.2%) hypertensive, and 44 (16.9%) unstable. Hypertensive patients frequently had hypertension history (77.1%), presented with higher escape rhythms (39.1± 6.7 vs 31.5± 10.4 and 38.1± 9.9 in unstable and normotensive patients respectively) and exhibited higher ejection fractions (58.2±8 vs 53.2±12 and 53.9±11 respectively). They demonstrated fewer low cardiac output signs, including acute kidney injury and elevated lactate levels. PVR was significantly elevated in the hypertensive group. The unstable group experienced the highest 30-day mortality and higher 1-year mortality, though the latter did not reach statistical significance. Factors independently associated with a hypertensive response included higher heart rate, higher ejection fraction, and calcium channel blocker pretreatment.

Conclusion: Hemodynamic presentations in high-degree AV block are heterogeneous. A hypertensive response represents a distinct clinical phenotype characterized by preserved cardiac function, higher escape rhythms, increased PVR, and fewer end-organ hypoperfusion signs.