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Left ventricular performance in coronary artery disease by systolic time intervals and echocardiography
Insights
Noninvasive measures like PEP/LVET and deltaD% effectively detect left ventricular dysfunction after myocardial infarction. These methods are more sensitive than clinical assessments or chest X-rays for identifying cardiac issues in post-MI patients.
Area of Science:
- Cardiology
- Noninvasive Cardiac Diagnostics
Background:
- Left ventricular (LV) dysfunction is a common complication following myocardial infarction (MI).
- Accurate detection of LV dysfunction is crucial for patient management and prognosis.
- Traditional clinical assessments and chest X-rays have limitations in detecting subclinical LV dysfunction.
Purpose of the Study:
- To evaluate the sensitivity of noninvasive measures, specifically systolic time intervals and echocardiographic parameters, in detecting left ventricular dysfunction in patients post-myocardial infarction.
- To compare the efficacy of these noninvasive measures against clinical findings and chest X-ray in identifying LV abnormalities.
Main Methods:
- Systolic time intervals (e.g., PEP/LVET) and echocardiographic measures (e.g., deltaD%) were assessed in 37 post-MI patients and 25 healthy controls.
- Patients were evaluated for symptoms of dyspnea, fatigability, and angina pectoris.
- Coronary arteriography was performed in a subset of patients (n=26).
- Phonocardiography (S3, S4) and chest X-ray (C/T ratio) were also utilized.
Main Results:
- Post-MI patients showed significant differences in noninvasive measures compared to controls.
- PEP/LVET and deltaD% were the most sensitive indicators of LV dysfunction, identifying abnormalities in 65-85% of asymptomatic patients.
- Abnormal LV performance correlated with the extent of coronary artery obstruction (higher prevalence in multi-vessel disease).
- Phonocardiography and chest X-ray findings were less reliable in detecting LV dysfunction.
Conclusions:
- Noninvasive measures, particularly PEP/LVET and deltaD%, demonstrate high sensitivity and superiority over clinical methods and chest X-rays for detecting left ventricular dysfunction in post-myocardial infarction patients.
- These noninvasive techniques are valuable tools for identifying subclinical LV impairment, even in asymptomatic individuals.
Abstract:
Determinations of systolic time intervals and echocardiographic measures of left ventricular performance were made in twenty-five normal subjects and 37 patients who had convalesced from a previous transmural myocardial infarction. On group analysis the patients with previous myocardial infarction demonstrated significant differences from the normals in each of the noninvasive measures. Among the noninvasive measures the PEP/LVET and deltaD% proved to be the most sensitive indicators of left ventricular dysfunction. Deviations from the normal range in PEP/LVET and deltaD% occurred in 65% to 70% of patients asymptomatic for dyspnea and fatigability (20 patients) and in 85% of patients asymptomatic for angina pectoris (13 patients). Neither the presence of phonocardiographically documented S3 or S4 or the finding of an abnormal C/T ratio on standard chest x-ray reliably detected patients with abnormal left ventricular performance. Among 26 patients studied by coronary arteriography, abnormal left ventricular performance by PEP/LVET and deltaD% occurred in less than 30% of those with obstruction (70% or greater) of one coronary artery and in over 80% of those with obstruction of two or three major arteries. A close correlation existed between the level of left ventricular performance measured by the PEP/LVET and the deltaD% (r = 0.93). These studies document the high degree of sensitivity of the noninvasive measures and demonstrate their superiority over clinical methods for detecting abnormal left ventricular performance in patients with previous myocardial infarction.