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Low Heart Rate Is Associated with Cerebral Pulsatility after TIA or Minor Stroke
Author(s) -
Webb Alastair J.S.,
Wartolowska Karolina A.,
Li Linxin,
Rothwell Peter M.
Publication year - 2022
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.26480
Subject(s) - medicine , cardiology , middle cerebral artery , blood pressure , diastole , transcranial doppler , heart rate , anterior cerebral artery , coronary artery disease , stroke (engine) , cerebral blood flow , ischemia , mechanical engineering , engineering
Objective Beta‐blockers are beneficial in coronary artery disease but less so in stroke prevention and dementia, potentially due to reduced heart rate (HR). Cerebral pulsatility is strongly associated with cerebral small vessel disease (SVD) and may be increased by lower diastolic pressures resulting from longer cardiac cycles. Methods Patients 4–6 weeks after TIA or non‐disabling stroke (Oxford Vascular Study) underwent 5 minutes continuous monitoring of blood pressure (BP), electrocardiogram (ECG), and middle cerebral artery flow velocity (transcranial ultrasound). Beat‐to‐beat relationships between HR, blood pressure and Gosling's pulsatility index (MCA‐PI) are reported as beta‐coefficients from general linear models for each individual. Results Across 759 patients, average MCA‐PI during monitoring was associated with lower HR and diastolic BP (DBP) and greater systolic BP (SBP) (∆MCA‐PI per 10 bpm/mmHg: −0.02, −0.04, 0.03, all p < 0.001), with HR particularly associated with low end‐diastolic cerebral velocity (0.86, p = 0.014). Beat‐to‐beat HR was strongly associated with concurrent low DBP and high SBP, potentially mediating the association with greater beat‐to‐beat cerebral pulsatility (average ∆MCA‐PI vs HR/DBP/SBP unadjusted: −0.062, −0.052, 0.0092; adjusted for concurrent BP: −0.039, −0.11, 0.041). The beat‐to‐beat association between HR and MCA‐PI increased with age, beta‐blockers, arterial stiffness, low HR (age > 70 + HR < 65 vs age < 70 + HR > 65: −0.081 vs −0.024, interaction p < 0.001), and severe SVD on MRI (age > 70 + severe vs age < 70 + none: −0.087 vs −0.047, interaction p = 0.03), with interactions between age, severe SVD, and low HR synergistically increasing MCA‐PI. Interpretation Low HR is associated with greater cerebral pulsatility in patients with SVD, potentially mediated by lower diastolic blood flow and representing a novel potential treatment target. ANN NEUROL 2022;92:909–920