Successful use of wearable cardioverter defibrillator in a patient with dextrocardia and persistent left superior vena cava

Atrial Flutter Masquerading as an ST-segment-elevation Myocardial Infarction in a Patient with Dextrocardia

Electrocardiogram (ECG) findings suggestive of an ST-segment–elevation myocardial infarction (STEMI) often lead to emergent left heart catheterization. Occasionally, non-coronary conditions mimic ECG findings of STEMI, resulting in an increased risk and expenses from emergent transportation and procedures. In this report, we describe diagnostic and management strategies for a case of 1:1 atrial flutter in a patient with dextrocardia presenting as a STEMI.

Computational Model for Therapy Optimization of Wearable Cardioverter Defibrillator: Shockable Rhythm Detection and Optimal Electrotherapy

Wearable cardioverter defibrillator (WCD) is a life saving, wearable, noninvasive therapeutic device that prevents fatal ventricular arrhythmic propagation that leads to sudden cardiac death (SCD). WCD are frequently prescribed to patients deemed to be at high arrhythmic risk but the underlying pathology is potentially reversible or to those who are awaiting an implantable cardioverter-defibrillator. WCD is programmed to detect appropriate arrhythmic events and generate high energy shock capable of depolarizing the myocardium and thus re-initiating the sinus rhythm. WCD guidelines dictate very high reliability and accuracy to deliver timely and optimal therapy. Computational model-based process validation can verify device performance and benchmark the device setting to suit personalized requirements. In this article, we present a computational pipeline for WCD validation, both in terms of shock classification and shock optimization. For classification, we propose a convolutional neural network-"Long Short Term Memory network (LSTM) full form" (Convolutional neural network- Long short term memory network (CNN-LSTM)) based deep neural architecture for classifying shockable rhythms like Ventricular Fibrillation (VF), Ventricular Tachycardia (VT) vs. other kinds of non-shockable rhythms. The proposed architecture has been evaluated on two open access ECG databases and the classification accuracy achieved is in adherence to American Heart Association standards for WCD. The computational model developed to study optimal electrotherapy response is an in-silico cardiac model integrating cardiac hemodynamics functionality and a 3D volume conductor model encompassing biophysical simulation to compute the effect of shock voltage on myocardial potential distribution. Defibrillation efficacy is simulated for different shocking electrode configurations to assess the best defibrillator outcome with minimal myocardial damage. While the biophysical simulation provides the field distribution through Finite Element Modeling during defibrillation, the hemodynamic module captures the changes in left ventricle functionality during an arrhythmic event. The developed computational model, apart from acting as a device validation test-bed, can also be used for the design and development of personalized WCD vests depending on subject-specific anatomy and pathology.

Implantation of VVI pacemaker in a patient with dextrocardia, persistent left superior vena cava, and sick sinus syndrome: A case report

BACKGROUND

Dextrocardia, or right-lying heart, is an uncommon congenital heart disease in which the apex of the heart is located on the right side of chest. Persistent left superior vena cava (PLSVA) is a rare venous anomaly that is often associated with the abnormalities of cardiac transduction system. A case with combination of dextrocardia, persistent left superior vena cava, and sick sinus syndrome has not been reported.

METHODS

We used different techniques including cardiac color Doppler echocardiography, 24-hour Holter monitoring, and abdominal ultrasound to make a diagnosis and treated the patient by implanting a VVI pacemaker.

RESULTS

A 50-year-old woman was admitted with a syncope. Angiography of the right atrium and superior vena cava, echocardiography, electrocardiography, and abdominal ultrasound revealed the presence of the combination of mirror image dextrocardia, PLSVA, and sick sinus syndrome. The complex structural anomalies presented great technical challenges for interventional treatments. After thorough examination and understanding of the structural anatomy and anomalies of the superior and inferior vena cava and cardiac chambers, we successfully treated this patient by implanting a VVI pacemaker.

CONCLUSION

Physicians must be aware of the complexity of the morphological and anatomical structures of dextrocardia accompanying PLSVC. Given that the diagnosis of situs inversus was performed at a relatively advanced age, it is therefore important to make such a correct diagnosis followed by appropriate therapeutic intervention.

The Wearable Cardioverter/Defibrillator - Toy Or Tool?

After the success story of implantable cardioverter/defibrillator systems, prevention of sudden cardiac death (SCD) remains one of the main duties in cardiology. For patients with unkown or transient risk profile for SCD, a wearable cardioverter/defibrillator (WCD) has been established for temporary and effective prevention of sudden arrhythmic death. Several studies have shown safety and efficacy of the WCD, even though randomized studies proving a mortality benefit are still lacking. This review provides an overview of actual WCD data and usage, special indications and possible risks and complications. WCD use is effective and adequate for temporary prevention of SCD in chosen populations. In particular, it provides secured time for sophisticated risk stratification to identify patients at persistent risk for SCD. Nevertheless, prospective randomized trials seem mandatory to prove a prognostic relevance and the economic value of this device.