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Absence of correlation between QRS duration and echographic parameters of ventricular desynchronization. Can we still
D Cozma1, D Lighezan, L Petrescu
1Institute of Cardiovascular Medicine, Timişoara, Romania.
Insights
In dilated cardiomyopathy (DCM) patients, QRS duration on ECG did not correlate with echocardiographic measures of ventricular desynchronization. However, mechanical desynchronization was present even with normal QRS duration, indicating its presence in heart failure.
Area of Science:
- Cardiology
- Echocardiography
- Heart Failure
Background:
- Dilated cardiomyopathy (DCM) is a significant cause of heart failure.
- Ventricular desynchronization can worsen heart failure symptoms and prognosis.
- Electrocardiogram (ECG) QRS duration is a common, albeit imperfect, indicator of ventricular desynchronization.
Purpose of the Study:
- To investigate the correlation between QRS duration on surface ECG and echocardiographic parameters of ventricular desynchronization in patients with DCM and severe heart failure.
- To determine if mechanical desynchronization is present in DCM patients with normal QRS duration.
Main Methods:
- 51 patients with idiopathic DCM were included.
- Measurements included QRS duration, effective contraction time (ECT), interventricular delay (IVD), and left ventricular delay (LVD).
- Regional wall delays and postsystolic contraction were also assessed.
Main Results:
- No correlation was found between QRS duration and echocardiographic parameters of ventricular desynchronization.
- Mechanical ventricular desynchrony was observed in patients with QRS duration < 120 ms.
- Postsystolic contraction and significant delays (LVD, IVD) were present in both LBBB and non-LBBB groups.
Conclusions:
- QRS duration is not a reliable predictor of echocardiographic ventricular desynchronization in DCM patients.
- Mechanical desynchronization can occur independently of prolonged QRS duration, highlighting the need for advanced imaging.
- Echocardiographic assessment is crucial for identifying desynchronization in heart failure patients, even with seemingly normal ECG findings.
Unlabelled:
The aim of the study was to assess if echographic ventricular desynchronization parameters measured in patients with dilated cardiomyopathy (DCM) and severe heart failure are correlated with the duration of the QRS on surface electrocardiogram.
Methods:
This study included 51 pts aged 58.8 +/- 7.4 years with idiopathic DCM. The following parameters were measured: QRS duration; effective contraction time (ECT) measured as the interval between QRS onset and closure of aortic valve, interventricular delay (IVD) measured as the time between onset of aortic and pulmonary flow, left ventricular mechanical delay (LVD) as the time from maximal interventricular septum contraction and posterior wall contraction, posterior (P), lateral (L) and posterolateral (PL) wall delays, as the time from QRS onset to maximal wall contraction. Regional postsystolic contraction was defined in a given wall as the difference (contraction delay - ECT)> 50ms.
Results:
29 pts presented complete LBBB, 22 pts had QRS duration < 120 ms. 39 pts had a postsystolic contraction of the PL wall (32 pts of the L wall and 26 pts of the P wall). 16 pts with QRS duration <120 had a postsystolic contraction of the PL wall (as for the LBBB the rest of 39 pts). In 40 pts the sequence of regional ventricular contraction was: P-L-PL wall (16 pts with QRS<120). LVD was > 100 ms in 36 pts (26 pts with LBBB and 10 with QRS<120). 27 of pts with LBBB and 6 with QRS <120 ms presented IVD> 30ms. There was no correlation between the QRS duration and the parameters listed above.
Conclusions:
In DCM pts there is no correlation between the duration of the QRS and echocardiographic parameters of ventricular desynchronization. Mechanical ventricular de-synchrony can be observed in patients with QRS duration < 120 ms.
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