Episodic syncope in hypertrophic cardiomyopathy

evidence for inappropriate vasodilation

K. Prasad, L Williams, R. Campbell, P M Elliott, W J McKenna, M Frenneaux

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Symptoms of impaired consciousness (syncope and presyncope) occur in 15-25% of patients with hypertrophic cardiomyopathy (HCM).(1) In young patients a history of recurrent syncope is associated with an increased risk of sudden death.(2) (5) Syncope usually occurs without warning or symptoms suggestive of the cause. Detailed investigations identify a probable mechanism in a minority, usually paroxysmal atrial fibrillation or ventricular tachycardia. In the majority however no likely mechanism is found despite repeated 24-hour ambulatory echocardiography (ECG) or patient-activated monitoring, exercise testing and invasive electrophysiological studies.(1) (6) Empirical treatment with amiodarone, a pacemaker or an implantable cardioverter-defibrillator is commonly employed, but is often unsuccessful in relieving the symptoms.

We have previously observed that approximately 30% of patients with HCM have abnormal blood pressure response during maximal upright exercise.(7) (8) This was due in the majority of patients to an exaggerated fall in systemic vascular resistance, possibly arising from abnormal activation of stretch-sensitive left ventricular mechanoreceptors,(9) (10) by a mechanism similar to that described in aortic stenosis.(11) However, in some patients an inadequate cardiac output response to exercise may be responsible.(12) We hypothesised that abnormal vasodepressor-mediated hypotension may also occur during daily life in patients with HCM, and that this may be an important mechanism of syncope when conventional investigations fail to reveal a cause.

Original languageEnglish
Pages (from-to)1312-1317
Number of pages6
JournalHeart
Volume94
Issue number10
Early online date24 Jul 2008
DOIs
Publication statusPublished - Oct 2008

Keywords

  • Blood-pressure response
  • healed myocardial-infarction
  • left-ventricular hypertrophy
  • abnormal vascular-responses
  • heart-rate-variability
  • sudden-death
  • conscious dogs
  • cardiac-output
  • arterial-pressure
  • exercise

Cite this

Prasad, K., Williams, L., Campbell, R., Elliott, P. M., McKenna, W. J., & Frenneaux, M. (2008). Episodic syncope in hypertrophic cardiomyopathy: evidence for inappropriate vasodilation. Heart, 94(10), 1312-1317. https://doi.org/10.1136/hrt.2008.141507

Episodic syncope in hypertrophic cardiomyopathy : evidence for inappropriate vasodilation. / Prasad, K.; Williams, L; Campbell, R.; Elliott, P M; McKenna, W J; Frenneaux, M.

In: Heart, Vol. 94, No. 10, 10.2008, p. 1312-1317.

Research output: Contribution to journalArticle

Prasad, K, Williams, L, Campbell, R, Elliott, PM, McKenna, WJ & Frenneaux, M 2008, 'Episodic syncope in hypertrophic cardiomyopathy: evidence for inappropriate vasodilation', Heart, vol. 94, no. 10, pp. 1312-1317. https://doi.org/10.1136/hrt.2008.141507
Prasad K, Williams L, Campbell R, Elliott PM, McKenna WJ, Frenneaux M. Episodic syncope in hypertrophic cardiomyopathy: evidence for inappropriate vasodilation. Heart. 2008 Oct;94(10):1312-1317. https://doi.org/10.1136/hrt.2008.141507
Prasad, K. ; Williams, L ; Campbell, R. ; Elliott, P M ; McKenna, W J ; Frenneaux, M. / Episodic syncope in hypertrophic cardiomyopathy : evidence for inappropriate vasodilation. In: Heart. 2008 ; Vol. 94, No. 10. pp. 1312-1317.
@article{df502ffb3fc94967bf25c4593c92e234,
title = "Episodic syncope in hypertrophic cardiomyopathy: evidence for inappropriate vasodilation",
abstract = "Symptoms of impaired consciousness (syncope and presyncope) occur in 15-25{\%} of patients with hypertrophic cardiomyopathy (HCM).(1) In young patients a history of recurrent syncope is associated with an increased risk of sudden death.(2) (5) Syncope usually occurs without warning or symptoms suggestive of the cause. Detailed investigations identify a probable mechanism in a minority, usually paroxysmal atrial fibrillation or ventricular tachycardia. In the majority however no likely mechanism is found despite repeated 24-hour ambulatory echocardiography (ECG) or patient-activated monitoring, exercise testing and invasive electrophysiological studies.(1) (6) Empirical treatment with amiodarone, a pacemaker or an implantable cardioverter-defibrillator is commonly employed, but is often unsuccessful in relieving the symptoms.We have previously observed that approximately 30{\%} of patients with HCM have abnormal blood pressure response during maximal upright exercise.(7) (8) This was due in the majority of patients to an exaggerated fall in systemic vascular resistance, possibly arising from abnormal activation of stretch-sensitive left ventricular mechanoreceptors,(9) (10) by a mechanism similar to that described in aortic stenosis.(11) However, in some patients an inadequate cardiac output response to exercise may be responsible.(12) We hypothesised that abnormal vasodepressor-mediated hypotension may also occur during daily life in patients with HCM, and that this may be an important mechanism of syncope when conventional investigations fail to reveal a cause.",
keywords = "Blood-pressure response, healed myocardial-infarction, left-ventricular hypertrophy, abnormal vascular-responses, heart-rate-variability, sudden-death, conscious dogs, cardiac-output, arterial-pressure, exercise",
author = "K. Prasad and L Williams and R. Campbell and Elliott, {P M} and McKenna, {W J} and M Frenneaux",
year = "2008",
month = "10",
doi = "10.1136/hrt.2008.141507",
language = "English",
volume = "94",
pages = "1312--1317",
journal = "Heart",
issn = "1355-6037",
publisher = "BMJ Publishing Group",
number = "10",

}

TY - JOUR

T1 - Episodic syncope in hypertrophic cardiomyopathy

T2 - evidence for inappropriate vasodilation

AU - Prasad, K.

AU - Williams, L

AU - Campbell, R.

AU - Elliott, P M

AU - McKenna, W J

AU - Frenneaux, M

PY - 2008/10

Y1 - 2008/10

N2 - Symptoms of impaired consciousness (syncope and presyncope) occur in 15-25% of patients with hypertrophic cardiomyopathy (HCM).(1) In young patients a history of recurrent syncope is associated with an increased risk of sudden death.(2) (5) Syncope usually occurs without warning or symptoms suggestive of the cause. Detailed investigations identify a probable mechanism in a minority, usually paroxysmal atrial fibrillation or ventricular tachycardia. In the majority however no likely mechanism is found despite repeated 24-hour ambulatory echocardiography (ECG) or patient-activated monitoring, exercise testing and invasive electrophysiological studies.(1) (6) Empirical treatment with amiodarone, a pacemaker or an implantable cardioverter-defibrillator is commonly employed, but is often unsuccessful in relieving the symptoms.We have previously observed that approximately 30% of patients with HCM have abnormal blood pressure response during maximal upright exercise.(7) (8) This was due in the majority of patients to an exaggerated fall in systemic vascular resistance, possibly arising from abnormal activation of stretch-sensitive left ventricular mechanoreceptors,(9) (10) by a mechanism similar to that described in aortic stenosis.(11) However, in some patients an inadequate cardiac output response to exercise may be responsible.(12) We hypothesised that abnormal vasodepressor-mediated hypotension may also occur during daily life in patients with HCM, and that this may be an important mechanism of syncope when conventional investigations fail to reveal a cause.

AB - Symptoms of impaired consciousness (syncope and presyncope) occur in 15-25% of patients with hypertrophic cardiomyopathy (HCM).(1) In young patients a history of recurrent syncope is associated with an increased risk of sudden death.(2) (5) Syncope usually occurs without warning or symptoms suggestive of the cause. Detailed investigations identify a probable mechanism in a minority, usually paroxysmal atrial fibrillation or ventricular tachycardia. In the majority however no likely mechanism is found despite repeated 24-hour ambulatory echocardiography (ECG) or patient-activated monitoring, exercise testing and invasive electrophysiological studies.(1) (6) Empirical treatment with amiodarone, a pacemaker or an implantable cardioverter-defibrillator is commonly employed, but is often unsuccessful in relieving the symptoms.We have previously observed that approximately 30% of patients with HCM have abnormal blood pressure response during maximal upright exercise.(7) (8) This was due in the majority of patients to an exaggerated fall in systemic vascular resistance, possibly arising from abnormal activation of stretch-sensitive left ventricular mechanoreceptors,(9) (10) by a mechanism similar to that described in aortic stenosis.(11) However, in some patients an inadequate cardiac output response to exercise may be responsible.(12) We hypothesised that abnormal vasodepressor-mediated hypotension may also occur during daily life in patients with HCM, and that this may be an important mechanism of syncope when conventional investigations fail to reveal a cause.

KW - Blood-pressure response

KW - healed myocardial-infarction

KW - left-ventricular hypertrophy

KW - abnormal vascular-responses

KW - heart-rate-variability

KW - sudden-death

KW - conscious dogs

KW - cardiac-output

KW - arterial-pressure

KW - exercise

U2 - 10.1136/hrt.2008.141507

DO - 10.1136/hrt.2008.141507

M3 - Article

VL - 94

SP - 1312

EP - 1317

JO - Heart

JF - Heart

SN - 1355-6037

IS - 10

ER -