Author + information
- Mayooran Namasivayam, MBBS, BSc (Med),
- Michael McCready, MD,
- Audrey Adji, MB, MBiomedE, PhD and
- Michael F. O’Rourke, MD, DSc∗ ()
- ↵∗Department of Cardiology, St. Vincent’s Hospital and Clinic, 438 Victoria Street, Suite 810, Darlinghurst, New South Wales, 2010, Australia
We read with interest the paper by McEvoy et al. (1) describing the association between low diastolic blood pressure and adverse clinical and subclinical (elevated troponin level) cardiovascular outcomes. The authors postulate that low diastolic blood pressure impairs coronary perfusion and thus causes adverse cardiac events. This mechanism is certainly plausible, but we wonder whether heart rate could have had an influence on the observed results. Heart rate affects diastolic pressure-time index, which is more important than diastolic pressure alone in determining coronary perfusion (2). Diastolic perfusion index is strongly influenced by heart rate and cardiac ejection duration, as demonstrated in large cohorts of both cardiology outpatients (3) and healthy volunteers (4). Additionally, the role of systolic pressure-time loading and its relationship to diastolic pressure-time index and overall myocardial oxygenation (i.e., myocardial demand–supply ratio) (2–4) is important to consider, and is itself strongly affected by heart rate and cardiac ejection duration. The findings of McEvoy et al. (1) highlight an important clinical issue—maintenance of adequate diastolic blood pressure to facilitate coronary perfusion. We would be interested to know to what extent heart rate interacted with their findings.
Please note: Dr. O’Rourke is a founding director of AtCor Medical and Aortic Wrap P/L. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2017 American College of Cardiology Foundation
- McEvoy J.W.,
- Chen Y.,
- Rawlings A.,
- et al.
- Namasivayam M.,
- McEniery C.,
- Wilkinson I.,
- et al.