No abstract

Cardiac resynchronization therapy is interrupted in more than one-third of patients after the successful implantation of a CRT-D device. However, CRT can be reinstituted in most patients and has a high long-term retention rate. Because patients with slower heart rates were more likely to develop atrial tachyarrhythmias, a dual-chamber rate-modulated pacing mode (DDDR) may reduce interruptions of CRT.

Intravenous amiodarone shows much promise for the short-term treatment of unstable arrhythmias. Its favorable hemodynamic effects and minimal short-term side effects make it an attractive option in the management of cardiac arrhythmias.

Laser lead extraction in the coronary sinus appears feasible in carefully selected cases with mandatory indications. However, special intraoperative monitoring and echocardiographic imaging with surgical backup ready is strongly recommended. Target vein selection may be limited for the purpose of reimplantation when leads are indwelling for greater than 3 months.

No abstract

In a select population of advanced heart failure patients receiving a CRT-D, NYHA class IV CHF was a powerful independent predictor of appropriate ICD therapy. Approximately one-quarter of the patients with NYHA class IV CHF who received a CRT-D device received an appropriate ICD therapy within 3 months after implant. Additional studies are needed to confirm an association between class IV CHF symptoms and an increased frequency of ICD shocks.

The evaluation of adolescents with chest pain, elevated cardiac enzymes, and abnormal electrocardiograms (ECGs) continues to pose diagnostic and management dilemmas. Myocardial infarction is an uncommon finding in this population and alternative diagnoses must be considered. Our database was retrospectively reviewed for adolescents age 16-18 years without prior cardiac history who underwent cardiac catheterization. Patients who presented with chest pain, elevated cardiac enzymes, normal ejection fraction, and abnormal ECGs were included. Management, diagnostic testing, and final diagnosis were reviewed. Nine adolescents (eight males and one female) without prior cardiac history were identified. The ECG findings in all patients were consistent with myocardial ischemia in a coronary distribution. Thrombotic coronary occlusion was not found in any patient. In adolescents without prior cardiac history of risk factors for myocardial infarction such as Kawasaki disease, familial hypercholesterolemia, or drug use who present with chest pain, multiple diagnoses must be considered even in the presence of focal ischemic ECG changes and elevated cardiac enzymes. Thrombolytic therapy or anticoagulation should be withheld until a definitive diagnosis of myocardial infarction has been made. Magnetic resonance imaging is the most useful tool to differentiate focal myocarditis from myocardial infarction.

HCU screening in a pacemaker clinic by a non-cardiologist can rapidly and accurately identify pacemaker recipients with at least moderate LV dysfunction who might be candidates for device upgrades. Ventricular dyssynchrony associated with RV pacing does not limit HCU identification of LV dysfunction.