Percutaneous closure of an iatrogenic atrial septal defect

Echocardiographic imaging of temporary percutaneous mechanical circulatory support devices

Cardiogenic shock is a state of end-organ hypoperfusion due to primary cardiac dysfunction and portends a poor prognosis. Shock refractory to inotropic and vasopressor support is often an indication for mechanical circulatory support. When mechanical support device complications or malfunction arise, echocardiography offers rapid assessment of device position and function. Repositioning can be done under echocardiographic guidance. Despite the widespread use of percutaneous mechanical circulatory support, there is a dearth of information regarding echocardiography as it pertains to these devices. In this review, we discuss the utility of echocardiography with percutaneous mechanical circulatory support devices.

Imaging for Temporary Mechanical Circulatory Support Devices

Heart failure is an important cause of mortality and morbidity in the world. Changes in organ allocation for solid thoracic (lung and heart) transplantation has increased the number of patients on mechanical circulatory support. Temporary mechanical support devices include devices tht support the circulation directly or indirectly such as extracorporeal membrane oxygenation (ECMO) and temporary support for right-sided failure, left-sided failure or biventricular failure. Most often, these devices are placed percutaneously and require either guidance with echocardiography, continuous radiography (fluoroscopy) or both. Furthermore, these devices need imaging in the intensive care unit to confirm continued accurate placement. This review contains the imaging views and nuances of the temporary assist devices (including ECMO) at the time of placement and the complications that can be associated with each individual device.

Mechanical circulatory support for cardiogenic shock

Cardiogenic shock (CS) is a syndrome of progressive depression of myocardial function with systemic hypoperfusion. It occurs due to various aetiologies such as acute myocardial infarction, myocarditis, acute decompensated heart failure and postcardiotomy. Cardiogenic shock carries poor prognosis, and medical therapy alone is not effective. Mechanical circulatory support is required to unload the ventricles, decrease the myocardial demand, prevent further injury, improve the coronary perfusion, stabilise the haemodynamics and maintain the end-organ perfusion before definitive interventions such as coronary reperfusion can take place. Currently, there are several methods of mechanical circulatory support. These include extracorporeal life support, paracorporeal or extracorporeal ventricular-assist devices, percutaneous ventricular assist devices, intra-aortic balloon counterpulsation and total artificial heart. In this review, we discuss the role of each of these circulatory support devices in the management of acute cardiac failure.

The role of percutaneous left ventricular assist devices during ventricular tachycardia ablation

Ventricular tachycardia (VT) is a common but serious arrhythmia that significantly adds to the morbidity and mortality of patients with structural heart disease. Percutaneous catheter ablation has evolved to be standard therapy to prevent recurrent implantable cardioverter defibrillator shocks from VT in patients on antiarrhythmia medications. Procedural outcomes in patients with structural heart disease are often limited by haemodynamically unstable VT. Although substrate- and pace-mapping techniques have become increasingly popular for VT ablation, these approaches can often times may not address inducible clinical and non-clinical VTs. Activation and entrainment mapping can help the operator target VT exit sites in a precise fashion minimizing the amount of radiofrequency ablation needed for a successful ablation. An evolving alternative strategy that allows induction and mapping of VT in the setting of severe cardiomyopathy and haemodynamic instability is through maintaining perfusion with a percutaneous ventricular assist device (pVAD). This review will discuss these pVAD technologies, distinguish technical applications of use, highlight the published clinical experience, provide a clinical approach for support device selection, and discuss use of these technologies with current mapping and navigational systems.

The incidence and long-term clinical outcome of iatrogenic atrial septal defects secondary to transseptal catheterization with a 12F transseptal sheath

BACKGROUND

Studies assessing the presence of a residual iatrogenic atrial septal defect (iASD) after transseptal catheterization with 8F transseptal sheaths have suggested that the majority of these iASDs close within 6 months. However, these studies have been limited by small patient numbers and short follow-up. Additionally, there are a number of novel catheter procedures in interventional cardiology and electrophysiology that use larger transseptal sheaths. The objective of this study was to assess the incidence of and complications associated with iASDs in a large cohort of patients undergoing transseptal catheterization with a 12F transseptal sheath.

METHODS AND RESULTS

Patients (n=253) without a preexisting interatrial shunt undergoing WATCHMAN implantation as part of the PROTECT AF study were included in this current study. Patients underwent transesophageal echocardiography with echo-contrast immediately after the procedure and at 45 days and 6 months and 12 months. Eighty-seven percent of patients had an iASD immediately after the procedure, the majority of which sealed by 6 months (incidence of iASD, 34% at 45 days, 11% at 6 months, 7% at 12 months). Whereas the majority of iASDs were >3 mm in diameter immediately after the procedure, the minority of iASD were >3 mm during the follow-up period. Additionally, interatrial shunting was predominantly left-to-right when an iASD was present. There was no significant difference in the rate of stroke and/or systemic embolism during the follow-up period in patients with or without iASD.

CONCLUSIONS

Transseptal catheterization procedures with a large-diameter transseptal sheath have a high spontaneous closure rate of iASDs that is not associated with an increased rate of stroke/systemic embolization during long-term follow-up.