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Relation of left ventricular function and prognosis in hypertrophic cardiomyopathy: an angiographic study
Insights
Left ventricular function, particularly peak ejection and filling rates, is crucial for predicting sudden death risk in hypertrophic cardiomyopathy patients. Impaired systolic function in those with ventricular tachycardia indicates a higher risk of sudden cardiac events.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Medical Imaging
Background:
- Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease.
- Prognosis in HCM is variable, with sudden cardiac death being a significant concern.
- Left ventricular function plays a key role in HCM outcomes.
Purpose of the Study:
- To evaluate the relationship between left ventricular function and prognosis in patients with hypertrophic cardiomyopathy.
- To identify predictors of sudden death in HCM.
- To assess the role of ventricular tachycardia in predicting sudden death risk.
Main Methods:
- Digitization of left ventricular cineangiograms from 88 HCM patients at diagnosis.
- Derivation of measurements including left ventricular volume, ejection fraction, and peak ejection/filling rates.
- Analysis of outcomes including sudden death, death from heart failure, and survival.
- Ambulatory electrocardiographic monitoring to detect ventricular tachycardia.
Main Results:
- Patients who died suddenly exhibited lower peak ejection and filling rates compared to survivors.
- Sudden death was best predicted by increased end-diastolic volume, small end-systolic volume, and low peak filling rate.
- Ventricular tachycardia was detected in 25% of patients; impaired systolic function was associated with sudden death in this subgroup.
- Predictive accuracy of angiographic and clinical features for sudden death was limited.
Conclusions:
- Indexes of left ventricular function are important for identifying HCM patients at risk of sudden death.
- Impaired systolic function may be a critical determinant for sudden death in HCM patients with ventricular tachycardia.
- While ventricular tachycardia is a sensitive marker, it is not specific for predicting sudden death risk in HCM.
Abstract:
Left ventricular cineangiograms performed at the time of diagnosis in 88 patients with hypertrophic cardiomyopathy were digitized to evaluate the relation of left ventricular function and prognosis in hypertrophic cardiomyopathy. Eleven patients died suddenly after a mean follow-up period of 7.5 +/- 7 years, 10 patients died of congestive heart failure or after cardiac surgery and 67 were alive after a mean follow-up period of 8.6 +/- 4 years. Measurements of left ventricular volume, ejection fraction, peak rate of ejection and filling and time to peak rate of ejection and filling were derived from curves of ventricular volume and its rate of change during the cardiac cycle. Patients who died suddenly had a lower peak rate of ventricular ejection (stroke volume-normalized peak ejection rate 5.41 +/- 0.69 versus 6.24 +/- 1.33 s-1; p = 0.006) and lower peak rate of ventricular filling (end-diastolic volume-normalized peak filling rate 4.02 +/- 0.94 versus 4.88 +/- 1.53 s-1; p = 0.02) and stroke volume-normalized peak filling rate (4.75 +/- 1.08 versus 5.82 +/- 1.70 s-1; p = 0.01) compared with survivors. Stepwise regression analysis revealed that sudden death was best predicted by the combination of increased end-diastolic volume, small end-systolic volume and low peak filling rate (predictive accuracy 32%, false negative 18% and false positive 28%). The addition of clinical features and hemodynamic measurements to the analysis improved predictive accuracy to 43% (false negative 18% and false positive 18%). Ambulatory electrocardiographic monitoring performed in 57 of the 88 patients 1 month to 17 years (median 8 years) after diagnosis revealed ventricular tachycardia in 14 (25%). Of these, 10 who survived had hyperkinetic systolic function at diagnosis, whereas the 4 who died suddenly had impaired systolic function (end-diastolic volume-normalized peak ejection rate 5.93 +/- 1.2 versus 4.01 +/- 1.2 s-1, respectively; p = 0.04). In hypertrophic cardiomyopathy, ventricular tachycardia is a sensitive but nonspecific marker of adults who are at risk of sudden death. Impaired systolic function may be an important determinant of which patients with ventricular tachycardia die suddenly. This study shows that indexes of ventricular function contribute to the identification of patients at particular risk of sudden death. However, the predictive power of the clinical features and hemodynamic and angiographic measurements that could be assessed was poor.(ABSTRACT TRUNCATED AT 400 WORDS)