Cardiophile MD Archive

Conventional implantable defibrillators have a subcutaneous device and lead which is placed within the heart, through the venous system. Bardy GH et al has evaluated an entirely subcutaneous ICD and reported the preliminary results in NEJM. Initially they compared the thresholds for various configurations in 78 patients and later the best configuration in 49 patients [...]

Right ventricular apical pacing has been found to have certain disadvantages like progressive left ventricular dysfunction leading to heart failure and associated morbidity and mortality as well as a propensity for atrial fibrillation. Hence attempts were made to simulate the natural sequence of ventricular activation by alternate site ventricular pacing. Right ventricular sites which were [...]

EP tracing of ventricular premature complex The first two complexes are sinus beats. The A in these beats seen the coronary sinus electrode channels (CS910 to CS12) preced the V recorded in the HISP (His bundle proximal) channel. The QRS complexes of these beats are narrow as seen in the surface ECG recordings at the [...]

EP tracing during ventricular pacing (Click on the image for a larger view) EP tracing during ventricular pacing showing atrial ventricular activation. The CS 910 electrode is in the proximal coronary sinus while the CS12 electrode is in the distal coronary sinus. ‘A’ represents atrial activation and ‘V’ represents ventricular activation. The pacing stimulus is [...]

Hypersensitive carotid sinus syndrome is an exaggerated response to stimulation of the barorecptors in the carotid sinus and leads to bradycardia / hypotension and syncope. Three types of responses have been described: cardioinhibitory, vasodepressor and mixed. In cardioinhibitory type there is only bradycardia, and there is no fall in blood pressure. The cardioinhbitory type is [...]