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[Left ventricular diastolic function in apical hypertrophic cardiomyopathy]
T Yamakado1, T Hayashi, S Ohkubo
1First Department of Internal Medicine, Mie University School of Medicine, Tsu.
Insights
Apical hypertrophic cardiomyopathy (AHCM) shows impaired left ventricular (LV) relaxation and reduced diastolic distensibility, similar to non-obstructive HCM. Early diastolic filling remains preserved in AHCM patients.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Medical Imaging
Context:
- Apical hypertrophic cardiomyopathy (AHCM) is a distinct form of HCM.
- Patients with AHCM often present with characteristic ECG and angiographic findings.
- Understanding diastolic dysfunction in AHCM is crucial for patient management.
Purpose:
- To assess left ventricular (LV) diastolic function in patients with AHCM.
- To compare diastolic parameters between AHCM, non-obstructive HCM (HNCM), and normal controls.
- To investigate the relationship between LV diastolic properties and specific clinical features in AHCM.
Summary:
- LV cineangiograms and pressures were analyzed in 11 AHCM patients, 10 HNCM patients, and 10 controls.
- LV isovolumic relaxation time constant (T) was prolonged, and diastolic pressure-volume relations were shifted upwards in both AHCM and HNCM groups compared to controls.
- Despite impaired relaxation and distensibility, LV early diastolic filling, assessed by peak filling rate (PFR), was preserved in AHCM.
Impact:
- The study reveals that impaired LV diastolic function, characterized by prolonged isovolumic relaxation and reduced distensibility, is a feature of AHCM.
- These findings suggest that diastolic dysfunction in AHCM may share mechanisms with HNCM.
- Preserved early diastolic filling in AHCM warrants further investigation into compensatory mechanisms and clinical implications.
Abstract:
To investigate left ventricular (LV) diastolic function in patients with apical hypertrophic cardiomyopathy (AHCM), we analyzed the LV cineangiograms (RAO 30 degrees) and pressures (tip manometer) in 11 patients with AHCM who had giant negative T waves on their electrocardiograms and "ace of spades" configurations on the LV angiograms. Ten patients with non-obstructive HCM (HNCM) and 10 normal subjects served as controls. LV volumes and instantaneous rates of LV volume changes were derived from frame-by-frame analyses of their LV angiograms. LV isovolumic relaxation was assessed according to the time constant (T) of LV pressure decay. LV diastolic distensibility was evaluated by plotting diastolic pressure-volume curves. There was no significant change in the LV systolic functions among these 3 groups. Compared with normals, LV end-diastolic pressure was equally elevated in AHCM and HNCM. The T of isovolumic pressure decay was significantly prolonged in AHCM and HNCM. LV early diastolic filling was maintained at the normal level in AHCM as assessed by the peak filling rate (PFR) during the rapid filling period and the time from end-systole to PFR. The LV diastolic pressure-volume relation shifted upwards in both AHCM and HNCM. In conclusion, impaired LV isovolumic relaxation and decreased diastolic distensibility, which are associated with HNCM, may also be present in AHCM.