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The imbalance between coronary reserve and wall stress explains the severity of ventricular dysfunction in

Clovis de Carvalho Frimm1, Valéria F A Pereira, Ana Clara T Rodrigues

  • 1Emergências Clínicas (LIM 51), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. frimm@emercli.fm.usp.br

Clinical Cardiology
|February 12, 2005
PubMed

Insights

Myocardial supply-demand imbalance worsens cardiac dysfunction in hypertension. Reduced coronary reserve/stress is linked to decreased fractional shortening, indicating impaired cardiac performance.

Area of Science:

  • Cardiovascular Physiology
  • Hypertension Research
  • Cardiac Dysfunction

Background:

  • The role of coronary reserve impairment in hypertensive cardiac dysfunction remains debated.
  • Previous findings showed coronary vasodilation can coexist with systolic dysfunction.
  • Inappropriate coronary reserve for heightened myocardial oxygen demand may negatively impact cardiac performance.

Purpose of the Study:

  • To investigate if myocardial supply-demand imbalance contributes to the severity of ventricular dysfunction in hypertension (HTN).
  • To assess the relationship between coronary reserve, end-systolic stress, and cardiac function in hypertensive individuals.

Main Methods:

  • Echocardiography was used to determine fractional shortening and end-systolic stress.
  • Transesophageal Doppler echocardiography calculated coronary reserve.
  • Coronary reserve/stress ratio served as a supply-demand measure in healthy subjects (NL) and hypertensive patients (HTN1-3) with varying fractional shortening.

Main Results:

  • Hypertensive groups HTN2 and HTN3 exhibited significantly greater end-systolic stress compared to NL and HTN1.
  • Coronary reserve was only impaired in HTN3, but coronary reserve/stress was reduced in both HTN2 and HTN3.
  • Diastolic internal dimension, end-systolic stress, and coronary reserve/stress independently correlated with fractional shortening.

Conclusions:

  • Supply-demand imbalance explains the severity of cardiac dysfunction in hypertension.
  • This imbalance provides additional insight into cardiac enlargement and elevated wall stress in hypertensive heart disease.
Abstract

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