Bradycardia
Conditions
Brief summary
The study is a prospective, randomized controlled study in hypertensive patients with a bradycardia indications for pacing therapy and a plan to receive dual-chamber pacemaker. Enrolled patients will be randomized 1:1 into the control group and the allometric-pace group. In the control group, the pacing lower rate will be set to the nominal 60 bpm post a dual-chamber pacemaker implantation as frequently used in clinical practice, while in the allometric-pace group, the pacing rate will be programmed at 75 bpm based on the estimation for Chinese population with a height of 165-170 cm (also called personalized lower rate) or based on the symptom-relief per clinical assessment by the study physicians. Each patient will undergo baseline assessments and 3-month follow-up visits. At the enrollment and office visits, each patient will undergo arterial blood pressure measurement, cardiac functional assessment and cerebral blood flow measurement. At the end of the study, the study physician will adjust pacing lower rate based on patients' conditions and clinical assessments. After the completion of the study, all patients will have regular device follow-up visit, usually 6-month interval or annually. Each patient will receive the following major assessments: device performance and pacing percentages, ventricular diastolic function by doppler and echocardiography of LVEF, LVEDV, LVESV, stroke volume, cardiac output, arterial blood pressure measurements, cerebral blood flow by MRI or Echo (which one will be determined later by the study PIs), and Mini-Mental State Examination (MMSE).
Interventions
The intervention consists of programming the pacemaker lower rate to a personalized setting of 75 beats per minute (personalized lower rate, PLR), based on clinical assessment. The control condition uses the standard pacemaker lower rate programmed at 50-60 beats per minute. No additional procedures beyond routine clinical practice are introduced.
The control intervention consists of programming the pacemaker lower rate to the standard clinical setting of 50-60 beats per minute, according to routine clinical practice. No additional procedures or deviations from standard care are introduced.
Sponsors
Study design
Eligibility
Inclusion criteria
* ≥65 years of age * Planned implantation of a dual chamber pacemaker with physiological pacing * Resting sinus heart rate ≤60 bpm, or average 24 hour Holter heart rate ≤60 bpm * Documented history of hypertension or office systolic blood pressure ≥130 mmHg
Exclusion criteria
* Diagnosis of secondary hypertension * Diagnosis of or possible concomitant heart failure, with ejection fraction ≤50% * Paroxysmal, persistent, or permanent atrial fibrillation * Status post CABG or PCI * Structural heart disease * Risk of ventricular tachyarrhythmia * Severe hepatic or renal dysfunction * Active acute infection * Inability to sign informed consent * Pregnancy or planned pregnancy during the study period * Enrollment in other clinical studies that may affect the objectives of this study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Ventricular Diastolic Function and Cerebral Blood Flow | Baseline to 6 months post-implantation | In hypertensive patients with sinus node dysfunction treated with dual chamber pacemaker implantation, compared with the control group (pacemaker lower rate 50-60 bpm), to verify whether ventricular diastolic function and cerebral blood flow can be improved by personalized lower rate pacing (PLR) (75 bpm). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cardiac Structure and Function Assessment | Baseline to 6 months post-implantation | To evaluate cardiovascular function using echocardiography and assess ventricular function, particularly diastolic function, using Doppler echocardiography. |
| Cerebral Perfusion and Cognitive Function Assessment | Baseline to 6 months post-implantation | To evaluate cerebral cortical blood distribution and white matter changes using magnetic resonance imaging (MRI), and to assess cognitive function using the Mini Mental State Examination (MMSE). |
| Arterial Blood Pressure Assessment | Baseline to 6 months post-implantation | To evaluate changes in arterial blood pressure using office blood pressure measurement and 24 hour ambulatory blood pressure monitoring. |