Impact of Allometric Pacing Rate on Ventricular Diastolic Function and Cerebral Blood Flow in Hypertensive Patients With Sinus Node Dysfunction

Overview

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

• Device Personalized lower rate pacing
  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.
• Device Standard lower rate pacing
  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.

Primary outcome measures

• Change in Ventricular Diastolic Function and Cerebral Blood Flow [Time frame: Baseline to 6 months post-implantation]

Secondary outcome measures (3)

• Cardiac Structure and Function Assessment [Time frame: Baseline to 6 months post-implantation]
• Cerebral Perfusion and Cognitive Function Assessment [Time frame: Baseline to 6 months post-implantation]
• Arterial Blood Pressure Assessment [Time frame: Baseline to 6 months post-implantation]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• Changes in 24-hour ambulatory systolic blood pressure following pacemaker implantation in patients with sinus node dysfunction. Presented at the APHRS 2025 Scientific Sessions; 2025; Poster presentation.
• Meng L, Hou W, Chui J, Han R, Gelb AW. Cardiac Output and Cerebral Blood Flow: The Integrated Regulation of Brain Perfusion in Adult Humans. Anesthesiology. 2015 Nov;123(5):1198-208. doi: 10.1097/ALN.0000000000000872. PMID 26402848
• Meyer M, LeWinter MM. Heart Rate and Heart Failure With Preserved Ejection Fraction: Time to Slow beta-Blocker Use? Circ Heart Fail. 2019 Aug;12(8):e006213. doi: 10.1161/CIRCHEARTFAILURE.119.006213. Epub 2019 Aug 1. No abstract available. PMID 31525068
• Infeld M, et al. Allometric-Based Pacing Rate Improves Quality of Life in Bradycardia Patients. Presented at the HRS 2025 Scientific Sessions; 2025; Poster presentation.
• Infeld M, et al. A novel method to classify left bundle branch block with far-field intracardiac electrograms. Presented at the HRS 2025 Scientific Sessions; 2025; Poster presentation.
• Infeld M, Wahlberg K, Cicero J, Plante TB, Meagher S, Novelli A, Habel N, Krishnan AM, Silverman DN, LeWinter MM, Lustgarten DL, Meyer M. Effect of Personalized Accelerated Pacing on Quality of Life, Physical Activity, and Atrial Fibrillation in Patients With Preclinical and Overt Heart Failure With Preserved Ejection Fraction: The myPACE Randomized Clinical Trial. JAMA Cardiol. 2023 Mar 1;8(3):21 PMID 36723919
• Infeld M, Avram R, Wahlberg K, Silverman DN, Habel N, Lustgarten DL, Pletcher MJ, Olgin JE, Marcus GM, Meyer M. An approach towards individualized lower rate settings for pacemakers. Heart Rhythm O2. 2020 Dec;1(5):390-393. doi: 10.1016/j.hroo.2020.09.004. Epub 2020 Oct 6. No abstract available. PMID 33604585

Identifiers

NCT: NCT07589452 · Allometric-Cerebral Study

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗