How the left and right sides of the heart, as well as pulmonary venous drainage, adapt to an increasing degree of head-up tilting in hypertrophic cardiomyopathy

Differences from the normal heart

Marco Guazzi, Anna Maltagliati, Gloria Tamborini, Fabrizio Celeste, Mauro Pepi, Manuela Muratori, Marco Berti, Maurizio D. Guazzi

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Objectives. We aimed to assess the differences in the adaptive response of patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, as well as any association with increased susceptibility to the test. Background. Diastolic function contributes importantly in the adaptation of the normal heart to head-up tilting. This mechanism may be disturbed by an impaired relaxation in HCM. Methods. Twenty-one male patients with HCM (46 ± 6 years old) and 22 healthy men (44 ± 8 years) were studied using Doppler echocardiography after 1 and 10 min of head-up tilting at 20°, 40°and 60°. Results. In control subjects, tilting was associated with 1) a predominance of diastolic pulmonary venous flow and early left ventricular (LV) filling (atrium functioning as an open conduit); 2) right ventricular (RV) shrinkage; and 3) no LV dimensional variations. In patients with HCM, tilting was associated with 1) a prevalence of systolic pulmonary venous flow (atrium functioning as a reservoir in which filling depends on atrial relaxation and compliance) and late diastolic transmitral flow (atrium working as a booster pump); 2) LV shrinkage; and 3) no RV dimension variations. These mechanisms did not prevent stroke volume (SV) from decreasing at 40°and 60°in both groups. Because of a lower increase in heart rate (HR), a reduction in cardiac output (CO) was greater in patients with HCM. The responses were similar after 1 and 10 min of tilting in control subjects, whereas in patients, blood pressure (BP), SV and LV dimension fell more after 10 min. Conclusions. Adaptation of the normal heart to tilting is based on a ventricular interaction and LV diastolic properties; HCM relies on left atrial diastolic and systolic functions. An inadequate HR reaction to a fall in BP and SV in HCM (depressed reflexogenic activity) contributes to making CO more vulnerable by greater and more prolonged displacements. (C) 2000 by the American College of Cardiology.

Original languageEnglish
Pages (from-to)185-193
Number of pages9
JournalJournal of the American College of Cardiology
Volume36
Issue number1
DOIs
Publication statusPublished - Jul 2000

Fingerprint

Hypertrophic Cardiomyopathy
Drainage
Head
Lung
Stroke Volume
Cardiac Output
Heart Rate
Blood Pressure
Doppler Echocardiography
Blood Volume
Compliance

ASJC Scopus subject areas

  • Nursing(all)

Cite this

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title = "How the left and right sides of the heart, as well as pulmonary venous drainage, adapt to an increasing degree of head-up tilting in hypertrophic cardiomyopathy: Differences from the normal heart",
abstract = "Objectives. We aimed to assess the differences in the adaptive response of patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, as well as any association with increased susceptibility to the test. Background. Diastolic function contributes importantly in the adaptation of the normal heart to head-up tilting. This mechanism may be disturbed by an impaired relaxation in HCM. Methods. Twenty-one male patients with HCM (46 ± 6 years old) and 22 healthy men (44 ± 8 years) were studied using Doppler echocardiography after 1 and 10 min of head-up tilting at 20°, 40°and 60°. Results. In control subjects, tilting was associated with 1) a predominance of diastolic pulmonary venous flow and early left ventricular (LV) filling (atrium functioning as an open conduit); 2) right ventricular (RV) shrinkage; and 3) no LV dimensional variations. In patients with HCM, tilting was associated with 1) a prevalence of systolic pulmonary venous flow (atrium functioning as a reservoir in which filling depends on atrial relaxation and compliance) and late diastolic transmitral flow (atrium working as a booster pump); 2) LV shrinkage; and 3) no RV dimension variations. These mechanisms did not prevent stroke volume (SV) from decreasing at 40°and 60°in both groups. Because of a lower increase in heart rate (HR), a reduction in cardiac output (CO) was greater in patients with HCM. The responses were similar after 1 and 10 min of tilting in control subjects, whereas in patients, blood pressure (BP), SV and LV dimension fell more after 10 min. Conclusions. Adaptation of the normal heart to tilting is based on a ventricular interaction and LV diastolic properties; HCM relies on left atrial diastolic and systolic functions. An inadequate HR reaction to a fall in BP and SV in HCM (depressed reflexogenic activity) contributes to making CO more vulnerable by greater and more prolonged displacements. (C) 2000 by the American College of Cardiology.",
author = "Marco Guazzi and Anna Maltagliati and Gloria Tamborini and Fabrizio Celeste and Mauro Pepi and Manuela Muratori and Marco Berti and Guazzi, {Maurizio D.}",
year = "2000",
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T1 - How the left and right sides of the heart, as well as pulmonary venous drainage, adapt to an increasing degree of head-up tilting in hypertrophic cardiomyopathy

T2 - Differences from the normal heart

AU - Guazzi, Marco

AU - Maltagliati, Anna

AU - Tamborini, Gloria

AU - Celeste, Fabrizio

AU - Pepi, Mauro

AU - Muratori, Manuela

AU - Berti, Marco

AU - Guazzi, Maurizio D.

PY - 2000/7

Y1 - 2000/7

N2 - Objectives. We aimed to assess the differences in the adaptive response of patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, as well as any association with increased susceptibility to the test. Background. Diastolic function contributes importantly in the adaptation of the normal heart to head-up tilting. This mechanism may be disturbed by an impaired relaxation in HCM. Methods. Twenty-one male patients with HCM (46 ± 6 years old) and 22 healthy men (44 ± 8 years) were studied using Doppler echocardiography after 1 and 10 min of head-up tilting at 20°, 40°and 60°. Results. In control subjects, tilting was associated with 1) a predominance of diastolic pulmonary venous flow and early left ventricular (LV) filling (atrium functioning as an open conduit); 2) right ventricular (RV) shrinkage; and 3) no LV dimensional variations. In patients with HCM, tilting was associated with 1) a prevalence of systolic pulmonary venous flow (atrium functioning as a reservoir in which filling depends on atrial relaxation and compliance) and late diastolic transmitral flow (atrium working as a booster pump); 2) LV shrinkage; and 3) no RV dimension variations. These mechanisms did not prevent stroke volume (SV) from decreasing at 40°and 60°in both groups. Because of a lower increase in heart rate (HR), a reduction in cardiac output (CO) was greater in patients with HCM. The responses were similar after 1 and 10 min of tilting in control subjects, whereas in patients, blood pressure (BP), SV and LV dimension fell more after 10 min. Conclusions. Adaptation of the normal heart to tilting is based on a ventricular interaction and LV diastolic properties; HCM relies on left atrial diastolic and systolic functions. An inadequate HR reaction to a fall in BP and SV in HCM (depressed reflexogenic activity) contributes to making CO more vulnerable by greater and more prolonged displacements. (C) 2000 by the American College of Cardiology.

AB - Objectives. We aimed to assess the differences in the adaptive response of patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, as well as any association with increased susceptibility to the test. Background. Diastolic function contributes importantly in the adaptation of the normal heart to head-up tilting. This mechanism may be disturbed by an impaired relaxation in HCM. Methods. Twenty-one male patients with HCM (46 ± 6 years old) and 22 healthy men (44 ± 8 years) were studied using Doppler echocardiography after 1 and 10 min of head-up tilting at 20°, 40°and 60°. Results. In control subjects, tilting was associated with 1) a predominance of diastolic pulmonary venous flow and early left ventricular (LV) filling (atrium functioning as an open conduit); 2) right ventricular (RV) shrinkage; and 3) no LV dimensional variations. In patients with HCM, tilting was associated with 1) a prevalence of systolic pulmonary venous flow (atrium functioning as a reservoir in which filling depends on atrial relaxation and compliance) and late diastolic transmitral flow (atrium working as a booster pump); 2) LV shrinkage; and 3) no RV dimension variations. These mechanisms did not prevent stroke volume (SV) from decreasing at 40°and 60°in both groups. Because of a lower increase in heart rate (HR), a reduction in cardiac output (CO) was greater in patients with HCM. The responses were similar after 1 and 10 min of tilting in control subjects, whereas in patients, blood pressure (BP), SV and LV dimension fell more after 10 min. Conclusions. Adaptation of the normal heart to tilting is based on a ventricular interaction and LV diastolic properties; HCM relies on left atrial diastolic and systolic functions. An inadequate HR reaction to a fall in BP and SV in HCM (depressed reflexogenic activity) contributes to making CO more vulnerable by greater and more prolonged displacements. (C) 2000 by the American College of Cardiology.

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