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[Augmentation of left ventricular slow filling in hypertrophic cardiomyopathy]
Insights
The study found that a large slow filling wave (SFW) in trans-mitral flow is frequently observed in hypertrophic cardiomyopathy (HCM) patients, potentially indicating abnormal left ventricular relaxation. This finding aids in understanding HCM pathophysiology.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Background:
- Trans-mitral flow (TMF) analysis is crucial for assessing left ventricular diastolic function.
- The slow filling wave (SFW) represents a component of ventricular filling that requires further characterization.
- Hypertrophic cardiomyopathy (HCM) is associated with diastolic dysfunction, making TMF analysis relevant.
Purpose of the Study:
- To investigate the significance of the augmented left ventricular slow filling wave (SFW) in various cardiac conditions.
- To determine the prevalence and characteristics of SFW in patients with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), mitral regurgitation (MR), old myocardial infarction (OMI), and normal controls.
- To explore the relationship between SFW patterns and left ventricular diastolic function indices.
Main Methods:
- Echocardiography with pulsed Doppler was used to observe TMF in 116 HCM, 74 DCM, 27 MR, 86 OMI patients, and 80 controls.
- The slow filling wave (SFW) was defined as a filling wave with a distinct peak velocity during the slow filling phase.
- SFW patterns were classified as large (S/E ≥ 1/2) or small (S/E < 1/2), and peak velocities (E, A, S) were measured.
Main Results:
- A large SFW was frequently observed in HCM patients (14%) but rarely in controls or other disease groups.
- Small SFW was more common in MR patients (37%) than controls (18%) and other groups, though not significantly.
- In HCM, patients with large SFW exhibited significantly lower early filling velocity (E) and prolonged isovolumic relaxation time, suggesting impaired relaxation.
Conclusions:
- The appearance of a large slow filling wave is a frequent finding in patients with hypertrophic cardiomyopathy (HCM).
- This large SFW may be indicative of abnormal left ventricular relaxation, a hallmark of HCM.
- TMF analysis, specifically the SFW pattern, can provide valuable insights into diastolic dysfunction in HCM.
Abstract:
To investigate the significance of augmentation of left ventricular slow filling, trans-mitral flow (TMF) was echocardiographically observed through pulsed Doppler method in 116 patients with hypertrophic cardiomyopathy (HCM), 74 with dilated cardiomyopathy (DCM), 27 with mitral regurgitation (MR), 86 with old myocardial infarction (OMI) and 80 normal controls (C). The slow filling-wave (SFW) in TMF was defined as the filling wave with obvious peak velocity during slow filling phase. The peak velocities (E, A, S) of the early filling, the atrial contraction and the slow filling waves were measured. The SFW was divided into two patterns according to the S and E ratio: large SFW (S/E greater than or equal to 1/2) and small SFW (S/E less than 1/2). 1) The small SFW was more frequently, but not significantly, observed patients with MR (37%) than in normal subjects (18%), patients with HCM (10%), DCM (4%) and OMI (7%). However large SFW was observed in 16 patients (14%) with HCM, but not in normal subjects and patients with other cardiac diseases excluding one patient with DCM. 2) In normal subjects and patients with DCM, OMI and MR, those with small SFW had larger E and smaller A/E than those without small SFW. However in patients with HCM, there was no difference in these indices (E and A/E) according to whether the patients were with or without SFW. 3) In HCM, patients with large SFW had significantly smaller E and significantly larger isovolumic relaxation time than those without SFW. Thus, appearance of the large slow filling wave, which might be caused by abnormal relaxation of the left ventricle, was frequently observed in patients with HCM.