Author + information
- Matthew G. Lloyd, PhD∗ ( and )
- Satish R. Raj, MD
- ↵∗Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
We read with interest the paper by Thibodeau et al. (1) describing the role of the clinical examination in patients with heart failure. Zema (2) should also be commended for his letter emphasizing the role of the Valsalva maneuver in the diagnosis of heart failure.
We regularly perform the Valsalva maneuver as part of routine autonomic function testing, because it provides a wealth of information regarding autonomic function. In our clinic, we regularly observe the non-normal Valsalva responses described by Zema (2), even in the absence of heart failure. It is important that clinicians are aware of differential causes of abnormal Valsalva variants.
Zema’s (2) discussion of abnormal Valsalva variants primarily focuses on phase 4. In healthy individuals, the blood pressure overshoot in phase 4 is caused by a combination of increased cardiac output (due to increased cardiac filling with release of the Valsalva) and sympathetically-mediated vasoconstriction (3) (Figure 1A). Therefore, diseases affecting sympathetic control of the vasculature (i.e., diabetes, Parkinson disease) will reduce or abolish the phase 4 blood pressure overshoot (Figure 1B). When assessing patients with heart failure, comorbidities affecting the sympathetic nervous system should be considered.
The most abnormal variant, the “square wave response” (noted in Figure 1 in Zema ) is indeed a strong indication of severe heart failure. However, we also see this pattern in young, healthy individuals without heart failure (Figure 1C), which can be eliminated with mild tilt (4). Although the underlying physiology is not well understood, it is important to note that this response can be a normal variant.
Lastly, the use of beat-to-beat blood pressure recording during the Valsalva maneuver is required for an optimal understanding of the hemodynamic responses, in particular the quantification of the phase 4 overshoot.
We hope that the caveats outlined in the preceding text provide added depth to this excellent discussion of the clinical examination of heart failure.
Please note: Dr. Lloyd has a post-doctoral scholarship through the Cummings School of Medicine. Dr. Raj is a network investigator of the Cardiac Arrhythmia Network of Canada (CANet; London, Ontario, Canada); and has served as a consultant to GE Healthcare and Lundbeck Pharmaceuticals LLC unrelated to the topic of this letter.
- 2019 American College of Cardiology Foundation
- Thibodeau J.,
- Drazner M.
- Zema M.J.
- Goldstein D.S.,
- Cheshire W.P.