ABSTRACT
Carotid sinus massage is a useful diagnostic and therapeutic maneuver in patients with supraventricular tachycardia. Abrupt tachycardia termination with carotid sinus massage typically indicates a mechanism dependent on the atrioventricular node. Here, we present the case of a 79-year-old patient presenting with a long-RP supraventricular tachycardia terminated with carotid sinus massage that was proven invasively to be due to a focal atrial tachycardia. We discuss mechanistic explanations for this unusual phenomenon and review the literature.
Subject(s)
Carotid Sinus , Electrocardiography , Massage/methods , Tachycardia, Supraventricular/diagnosis , Tachycardia, Supraventricular/physiopathology , Tachycardia, Supraventricular/therapy , Aged , Echocardiography , Female , HumansABSTRACT
True nodoventricular (NV) accessory connections, as originally described by Mahaim, are rare entities, with the majority of previously reported cases now recognized as being due to decremental atriofascicular pathways. Here, we present a patient with incessant narrow and wide QRS complex tachycardia occurring in the setting of prior complete heart block. Entrainment mapping proved useful in diagnosing orthodromic reentry utilizing a concealed right septal NV pathway. The patient was successfully treated with radiofrequency ablation, resulting in a marked improvement in left ventricular function.
Subject(s)
Cardiomyopathies/diagnosis , Cardiomyopathies/etiology , Electrocardiography/methods , Pre-Excitation, Mahaim-Type/complications , Pre-Excitation, Mahaim-Type/diagnosis , Tachycardia, Ventricular/complications , Tachycardia, Ventricular/diagnosis , Humans , Male , Middle AgedABSTRACT
Approximately 25% of patients diagnosed with symptomatic heart failure have evidence of significant intraventricular conduction delay defined by a QRS width greater than 120 ms. Heart failure leads to dysynchronous ventricular contraction, mechanical inefficiency and further impairment of left ventricular function. Patients with severe heart failure are also more likely to be burdened by mitral regurgitation. Biventricular pacing is a new therapy for heart failure refractory to standard pharmacological therapy. Biventricular pacing has been shown to improve the hemodynamics of patients with intraventricular conduction delay and low ejection fraction. This is done by simultaneous electrical stimulation of both ventricles. This is a review of recent evidence on the efficacy of biventricular pacemakers, cardiac resynchronization therapy, and the pathophysiology underlying the use of these therapies.
