Mitral valve prolapse: a source of arrhythmias?

Evaluation of Early Repolarization Pattern in Children with Mitral Valve Prolapse

BACKGROUND

Patients with mitral valve prolapse (MVP) may be prone to ventricular arrhythmias and sudden cardiac death and presence early repolarization pattern (ERP) in electrocardiography may be predict for ventricle arrhythmia. This study aimed to evaluation ERP in Children with MVP.

METHODS

In a cross-sectional study, we enrolled ERP in 70 MVP children with 70 age-and sex-matched healthy individuals. After echocardiography procedure for confirmation MVP, standard 12-lead electrocardiography recordings with sweeping rate of 25mm/s and an amplitude of 10mV/cm, and two cardiologists assessed who were blinded to the both groups.

RESULT

We detected ERP in 17.14% of MVP patient's and seen in 8 case (11.43%) in control group, (P=0.23). the ERP occurred in MVP patient's mild, moderate and severe 4, 6 and 2 cases, (P=0.29). The ERP found in patients with and without chest pain 13 and 7, respectively (P=0.46) and, in patients with and without palpitations 15 and 5 cases, respectively (P=0.24). The ERP occurred 1.6 time more in patient with MVP in comparing with individual without MVP. The ERP occurred more frequently in among patients with moderate MVP in comparing with severe and mild. Chest pain and palpitation occurred more frequently in among patients with severe MVP.

CONCLUSION

The prevalence of ERP in children with MVP has been at a higher-level incidence, especially among patients with complaining from chest pain. We suggested that children with MVP are in need of follow up considering the occurrence of arrhythmias.

Supraventricular arrhythmia in mitral valve prolapse : Predictive value of P-wave dispersion and atrial conduction time

BACKGROUND

The incidence of supraventricular arrhythmia (SVA) is high in patients with mitral valve prolapse (MVP). The purpose of our study was to determine the role of parameters showing atrial conduction heterogeneity such as P‑wave dispersion (PWD) and atrial electromechanical delay (AEMD) in predicting the development of SVA in MVP patients.

METHODS

A total of 76 patients with MVP (56 female, 20 male) were included in the study. The patients were divided into two groups according to the presence or absence of SVA: 36 patients were allocated to the non-SVA group and 40 patients to the SVA group. Heart rate variability (HRV), PWD, and AEMD values were determined and compared.

RESULTS

The PWD was found to be higher in the SVA group. Interatrial EMD was 32.00 ms (25.00-35.00) in patients with SVA while it was 18.00 ms in patients without SVA (11.00-23.75); the intra-atrial EMD was 17.0 ms (10.00-20.00) in patients with SVA whereas it was 10.00 ms (4.00-14.00) in patients without SVA. Lower HRV was found in the SVA group.

CONCLUSION

In the SVA group, PWD and AEMD were increased while HRV values were decreased. Noninvasive parameters may help predict the presence and incidence of SVA during the follow-up of this group of patients.

Fragmented QRS may be associated with complex ventricular arrhythmias in mitral valve prolapse

BACKGROUND

Although mitral valve prolapse (MVP) is a benign disease, several studies have indicated its association with ventricular arrhythmias (VAs). Some histopathological studies have pointed to left ventricular fibrosis as the underlying cause of arrhythmia in MVP patients. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. This study aimed to investigate the association between fQRS and complex VAs in patients with MVP.

METHODS

A total of 230 consecutive patients who were diagnosed with MVP were included in the study. The control group consisted of 302 healthy individuals matched according to age and sex. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All patients underwent 24-hour Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥3 VAs were considered as complex VAs.

RESULTS

As compared to the healthy individuals, prevalence of fQRS (40% vs. 9.6%, P<0.001) and complex VAs (18.7% vs. 0%, P<0.001) were significantly higher in patients with MVP. Furthermore, complex VAs (35.9% vs. 7.2%, P=0.001) were significantly higher in MVP patients with fQRS. In multiple logistic regression analysis, the presence of bileaflet prolapse (OR: 2.567, 95%CI: 1.434 to 4.367; P=0.002) and presence of fQRS (OR: 3.021, 95%CI: 1.556 to 6.232; P<0.001) were independent predictors for complex VAs.

CONCLUSIONS

The presence of fQRS may be associated with complex VAs in patients with MVP. Therefore, fQRS may be used in risk stratification of complex VAs in patients with MVP.

Heart Sound Segmentation-An Event Detection Approach Using Deep Recurrent Neural Networks

OBJECTIVE

In this paper, we accurately detect the state-sequence first heart sound (S1)-systole-second heart sound (S2)-diastole, i.e., the positions of S1 and S2, in heart sound recordings. We propose an event detection approach without explicitly incorporating a priori information of the state duration. This renders it also applicable to recordings with cardiac arrhythmia and extendable to the detection of extra heart sounds (third and fourth heart sound), heart murmurs, as well as other acoustic events.

METHODS

We use data from the 2016 PhysioNet/CinC Challenge, containing heart sound recordings and annotations of the heart sound states. From the recordings, we extract spectral and envelope features and investigate the performance of different deep recurrent neural network (DRNN) architectures to detect the state sequence. We use virtual adversarial training, dropout, and data augmentation for regularization.

RESULTS

We compare our results with the state-of-the-art method and achieve an average score for the four events of the state sequence of ${\bf F}_{1}\approx 96$% on an independent test set.

CONCLUSION

Our approach shows state-of-the-art performance carefully evaluated on the 2016 PhysioNet/CinC Challenge dataset.

SIGNIFICANCE

In this work, we introduce a new methodology for the segmentation of heart sounds, suggesting an event detection approach with DRNNs using spectral or envelope features.

Mitral valve prolapse: an underestimated cause of sudden cardiac death-a current review of the literature

Mitral valve prolapse (MVP) is a common valve abnormality in general population. Despite the general belief of a benign disorder, several articles since the 1980s report sudden cardiac death (SCD) in MVP patients, with a substantial percentage of asymptomatic young individuals. The problem is to detect those patients at increased risk and implement methods that are suitable to prevent cardiac arrest. This review investigates the correlation between MVP and SCD, the understanding of the pathophysiology, the strategies for detecting those at risk and treatment options. A complete literature survey was performed using PubMed database search to gather available information regarding MVP and SCD. A total of 33 studies met selection criteria for inclusion in the review. MVP is an underrated cause of arrhythmic SCD. The subset of patients with malignant MVP who may be at greater risk for SCD is characterized by young women with bileaflet MVP, biphasic or inverted T waves in the inferior leads, and frequent complex ventricular ectopic activity with documented ventricular bigeminy or ventricular tachycardia (VT) and premature ventricular contractions (PVCs) configurations of outflow tract alternating with fascicular origin or papillary muscle. MVP is a common condition in the general population and is often encountered in asymptomatic individuals. The existing literature continues to generate significant controversy regarding the association of MVP with ventricular arrhythmias and SCD. Early echocardiography and cardiac magnetic resonance (CMR) are essential, as is a greater understanding of the potential electrophysiological processes of primary arrhythmogenesis and the evaluation of the genetic substrate.

Prolonged Tp-e Interval and Tp-e/QT Ratio in Children with Mitral Valve Prolapse

Although it is considered to be a benign condition, previous studies have shown that a subset of patients with mitral valve prolapse (MVP) may be at risk of ventricular arrhythmia and sudden cardiac death (SCD). Previous studies have suggested that the interval between the peak and the end of the T wave (Tp-e) can be used as a marker for the transmural dispersion of repolarization. Increased Tp-e interval and Tp-e/QT ratio are associated with ventricular arrhythmias and SCD. The aim of this study was to assess alterations in ventricular repolarization by using the Tp-e interval and Tp-e/QT ratio in children with MVP and to investigate their relationships with the degree of valvular regurgitation. This study prospectively investigated 110 children with MVP and 107 age- and sex-matched healthy control subjects. Tp-e interval, Tp-e/QT ratio, and QT and QTc dispersions were measured from a 12-lead electrocardiogram and compared between groups. QT and QTc dispersions, Tp-e interval, and Tp-e/QTc ratio were found to be significantly higher in patients with MVP. A positive correlation was found between Tp-e/QTc ratio and increase in the degree of mitral regurgitation (MR) (p < 0.05; r = 0.2). However, the degree of MR was not associated with QT, QTc, or Tp-e intervals; QT, QTc, or Tp-e dispersions; or Tp-e/QT ratio (all p values >0.05). Individuals with MVP may be more prone to ventricular arrhythmias due to prolonged QTd, QTcd, and Tp-e interval and increased Tp-e/QT and Tp-e/QTc ratios. Therefore, due to their longer life expectancy, children with MVP should be followed up on regarding life-threatening arrhythmias.

Electrocardiographic changes in mitral valve prolapse syndrome

Introduction: Mitral valve prolapse syndrome (MVP) is the most common valvular abnormalityin the young and is correlated with increased frequency of cardiac dysrhythmias and sudden death.The aim of this study was to compare frequency of “early repolarization” in electrocardiogram(ECG) between MVP patients and healthy adults.

Methods: In this cross-sectional study, we compared ECG presentations of early repolarizationincluding notch in descending arm of QRS and J-point and/or ST segment changes in 100 patientswith MVP with 100 healthy individuals. MVP patients were referred to cardiology clinic withsymptoms of palpitation, chest pain or anxiety.

Results: The mean age in patients with MVP was significantly less than healthy subjects (29.5 ±9.3 years versus 31.0 ± 6.9 years in control group, P= 0.1967). We detected early repolarizationas a prevalent sign in ECG of patients which was a notch in descending arm of QRS and/or STsegment or J-point elevation seen in 74% of patients ( 51% in inferior leads and 23% in I and aVLleads) , whilst the same findings were seen in 8 men (8%) in control group (P= 0.0001).

Conclusion: Early repolarization in ECG presented as a notch in descending arm of QRS and/or ST segment or J-point elevation is more frequent in in young patients with MVP syndrome.