Heart rate reduction decreases central blood pressure in sick sinus syndrome patients with a permanent cardiac pacemaker

Abstract

Increased resting heart rate (HR) contributes to higher cardiovascular mortality and morbidity in the healthy as well as in people with cardiovascular diseases, possibly due to elevated blood pressure (BP) among other mechanisms. Data on the relationship between HR and central (aortic) BP remains controversial, however, and concerning β-blockers, it has been proposed that pharmacological HR lowering is associated with augmentation of central BP. We aimed to study the role of pharmacologically unaffected HR on central BP indices in sick sinus syndrome patients with a permanent cardiac pacemaker in the HR range from 40 to 90 bpm. We included 27 subjects (mean age 65.8 ± 9.5 years, 12 men) with a dual-chamber pacemaker implanted due to sick sinus syndrome. We determined central hemodynamic indices noninvasively during an atrial pacing mode at low (40 bpm), middle (60 bpm), and high (90 bpm) HR levels with an oscillometric cuff-based device (Sphygmocor XCEL). There was no difference in central systolic BP at the middle versus the high HR level (mean 121.2 ± 13.0 and 121.2 ± 12.1 mmHg, respectively, P = 0.9), but at the low HR level, it was significantly lower than at the middle HR level (mean 117.2 ± 13.1 and 121.2 ± 13.0 mmHg, P < 0.01). Our acute study provides evidence to suggest that at a HR of <60 bpm, sick sinus syndrome patients may have a lower central BP than at a higher HR, despite the proposed augmenting effects of low HR on central BP.

Atenolol’s Inferior Ability to Reduce Central vs Peripheral Blood Pressure Can Be Explained by the Combination of Its Heart Rate-Dependent and Heart Rate-Independent Effects

“…is was a nonrandomized single-blind single-group clinical trial conducted as an extension of our previous trial [10].…”

“…We recruited all participants from Tartu University Hospital, Estonia. Our recruitment strategy included preliminary screening of medical histories of past 5 years of adult sick sinus syndrome patients with a permanent dual-chamber cardiac pacemaker for eligibility criteria, followed by inviting patients considered eligible to an outpatient visit to undergo final screening including a 12lead electrocardiogram (ECG) and pacemaker interrogation [10].…”

Conceptos actuales sobre la clasificación clínica y alteraciones electrofisiológicas en la disfunción del nódulo sinusal

“…Actualmente se denomina disfunción del nódulo sinusal (DNS) a esta entidad nosológica. Los pacientes con este trastorno son a menudo añosos (aunque algunas publicaciones describen una distribución bimodal) y en general presentan otras comorbilidades (6)(7)(8)(9)(10) .…”

“…Las anomalías electrocardiográficas observadas (bradicardia, pausas sinusales, paro sinusal), frecuentemente se alternan con episodios paroxísticos de taquiarritmias supraventriculares (2,8) . Los pacientes a menudo buscan atención médica con síntomas de aturdimiento, presíncope, síncope y, en pacientes con periodos alternantes de bradicardia y taquicardia, palpitaciones u otros síntomas asociados con una frecuencia cardíaca rápida (3)(4)(5) .…”

“…Los pacientes a menudo buscan atención médica con síntomas de aturdimiento, presíncope, síncope y, en pacientes con periodos alternantes de bradicardia y taquicardia, palpitaciones u otros síntomas asociados con una frecuencia cardíaca rápida (3)(4)(5) . Debido a que los síntomas pueden ser de naturaleza variable, inespecíficos y frecuentemente transitorios, a veces puede ser difícil establecer esta relación síntomaalteración electrocardiográfica (8)(9)(10) . Los hallazgos electrocardiográficos típicos son uno o más episodios de bradicardia sinusal extrema (Rubenstein Tipo I), o pausas sinusales, paro y bloqueo de salida sinoatrial (Rubenstein Tipo II), o episodios de bradicardia y/o pausas alternantes con taquiarritmias auriculares (Rubenstein Tipo III) (2) .…”