Multiple shocks after upgrade of an implantable cardioverter-defibrillator to a cardiac resynchronization therapy-defibrillator device

Inappropriate shocks from implantable cardioverter-defibrillators (ICDs) may occur for many reasons. Inappropriate shocks are not simply painful inconveniences for patients; they also may result in the need for further operative procedures, and sometimes even death. Herein, we report the case of a patient who after upgrade of an ICD to a cardiac resynchronization therapy-defibrillator device (CRT-D), returned with multiple shocks due to altered sensing and defibrillation polarities that resulted from actual physical reversal of the distal (–) and proximal (+) lead terminals in the header of the device

Nodal and infranodal atrioventricular conduction block: Electrophysiological basis to correlate the ECG findings

A 68-year-old woman with a history of dilated non-ischemic cardiomyopathy presented with syncope. The index ECG showed sinus rhythm with left bundle branch block. On telemetry episodes of sinus rhythm with narrower QRS complexes conduced in 2:1 pattern were noted. Invasive electrophysiological study was performed to determine cause of syncope. Normal conduction up to the AV node with an AH interval of 79 ms (normal = 55–125 ms) was observed. However, every alternate sinus beat was blocked after the inscription of His deflection (infra-Hisian block). The narrow beats conducted through the His bundle with HV intervals of 54 ms (normal = 35–55 ms). When 1:1 conduction resumed further abnormality of the His–Purkinje conduction system became evident with a QRS morphology that of an LBBB and prolongation of HV interval (HV = 96 ms). Criteria to differentiate nodal versus infranodal block based on electrophysiological properties of the nodal and infranodal system are discussed

Effect of cardiac resynchronization therapy on diastolic dysfunction as assessed by transthoracic two-dimensional Doppler echocardiography.

Cardiac resynchronization therapy (CRT) in patients with left ventricular systolic dysfunction and electrical dyssynchrony has been shown to improve morbidity and mortality. Improvement in diastolic dysfunction may contribute to these results. In this retrospective study, the authors assessed the effect of CRT on the E/A ratio and mitral valve deceleration time, which are commonly utilized parameters of left ventricular diastolic function. In 13 patients (aged 62 +/- 11.3 years), the E/A ratio increased from 1.17 +/- 0.58 to 1.49 +/- 0.66 (p = nonsignificant) and the mitral valve deceleration time increased from 178.48+/-57.71 milliseconds to 227.70 +/- 76.18 milliseconds (p = 0.054) post-CRT. In patients without mitral regurgitation, there was a significant increase in E/A ratio, from 1.22 +/- 0.4 to 1.86 +/- 0.47 (p = 0.025), but no significant change in the mitral valve deceleration time post-CRT was observed. These data suggest improvement in diastolic dysfunction as assessed by routine two-dimensional echocardiography in patients who receive CRT devices

Ventricular tachycardia from intracardiac hematoma in the setting of blunt thoracic trauma

In the victims of motor vehicle accidents, unrecognized myocardial injuries may pose diagnostic and therapeutic challenges. Herein, we present a case of a 17-year-old man who developed multiple ventricular premature complexes and nonsustained ventricular tachycardia in the setting of blunt chest trauma from a motor vehicle accident. We discuss significance of the electrocardiographic abnormalities in making an accurate diagnosis of cardiac hematoma and its management

Diffuse cerebral air embolism treated with hyperbaric oxygen: a case report.

A 54-year-old woman presented for cardiac evaluation of atypical chest pain. Workup included coronary angiography and a left ventriculogram, during which air was inadvertently injected, resulting in the development of an acute right hemisphere syndrome. Right carotid angiography was immediately performed, yielding only a delayed diffuse venous phase without focal vessel cutoffs. Within 60 minutes, the patient underwent hyperbaric oxygen therapy for the suspected cerebral air emboli. After removal from the chamber for technical reasons, she had a generalized tonic-clonic seizure, and further hyperbaric oxygen therapy was withheld. Initial computed tomography imaging obtained approximately 8 hours after symptom onset showed signs of early right hemispheric edema. Subsequent magnetic resonance imaging studies were markedly abnormal and suggestive of diffuse bilateral but predominantly right-sided parietal lobe edema with mildly positive diffusion-weighted imaging. Follow-up magnetic resonance imaging at 6 months was normal, and the patient\u27s neurological examination returned to normal