Archives
A year old male with known dextrocardia and CCTGA presented
A 52-year-old male with known dextrocardia and CCTGA presented with a 2-month history of recurrent presyncope and effort intolerance. His examination revealed a resting pulse rate of 52beats/min (bpm) and a blood pressure of 130/80mmHg. The apex beat and heart sounds were appreciated on the right side of the sternum, whereas gastric tympany was noted below the left diaphragm. A 12-lead electrocardiogram (ECG) revealed sinus rhythm with an atrial rate of 80bpm, complete atrioventricular block, and a narrow QRS escape with a rate of 50bpm. The normal P wave axis (+60°) indicated normal atrial situs, the progressive decrease in the height of the R waves from V1 to V6 suggested dextrocardia, and the absence of septal q waves in the lateral leads was suggestive of CCTGA (Fig. 1). A posteroanterior chest radiograph confirmed dextrocardia with situs solitus. A transthoracic echocardiogram confirmed the diagnosis of situs solitus, dextrocardia, and CCTGA with adequate systemic ventricular function and no other associated abnormality. The temporary pacemaker lead, which was inserted from the right femoral vein just prior to PPI, was seen to course along a right-sided inferior vena cava, further confirming the atrial situs as solitus. Under local anesthesia using 1% lignocaine hydrochloride, a 3-cm long incision was made one fingerbreadth below the right buy norepinephrine bitartrate across the deltopectoral groove such that two-thirds of the incision was medial and one-third was lateral to the groove, and an attempt was made to isolate the cephalic vein. Since the cephalic vein was not of adequate caliber, venous access was obtained through two separate extrathoracic axillary venous punctures using an 18G needle and two guide wires that were inserted into the venous system. A 7F active fixation lead (model 4076, 58cm, Medtronic Inc., Minneapolis, MN, USA) was inserted through a 7F peel-away introducer (Medtronic Inc., Minneapolis, MN, USA) over one guide wire. The lead was manipulated into the pulmonary artery over a stillette that was given a distal curvature. The lead withdrawn from the pulmonary artery into the venous ventricle acquired a position that appeared to be septal in the anteroposterior (AP) view, but appeared to point laterally in the right anterior oblique view (RAO). Since the true position of the lead was not quite clear, angiographic delineation of the right heart chambers was considered an option. Through the second access that was meant for the atrial lead, a 6F valved introducer with a side port (AVANTI®+, Cordis Corporation, Miami, FL, USA) was inserted, and the distal tip was positioned in the superior vena cava. Through the side port, 10mL of non-ionic intravenous contrast (iohexol) was rapidly injected by hand, and cine films were acquired in the AP, left anterior oblique (LAO), and RAO views. This was performed to define the position of the venous atrium and its appendage, the relationship of the venous atrium to the venous ventricle, and anatomical details of the venous ventricle. The acquired films confirmed the lateral wall position of the previously placed lead and served as roadmaps to facilitate further lead positioning (Fig. 2). After failed attempts at obtaining a stable lead position in the septal region because of the smooth-walled morphologic left ventricle, the lead was screwed to the apex, where sensed R waves of 18mV, a threshold of 0.9V, pulse width of 0.4ms, and lead impedance of 780ohms were obtained. The 6F valved introducer was then exchanged over a guide wire for a 7F peel-away introducer, and an atrial straight active fixation lead (model 4076, 52cm, Medtronic Inc., Minneapolis, MN, USA) was inserted through it. The lead was positioned in the right atrial appendage over a curved stillette, with the previously acquired cine films serving as a roadmap. Satisfactory pacing parameters were obtained, with P waves of 4.4mV, threshold values of 0.5V at a pulse width of 0.5ms, and a lead impedance of 550ohms (Fig. 3). After confirming the stable positions of both leads, the leads were secured to the muscle. A dual chamber pulse generator (Model Relia DDD, Medtronic Inc., Minneapolis, MN, USA) was attached to the leads and placed in a pre-pectoral pocket, and the wound was closed in layers. A post-procedural 12-lead ECG revealed atrial sense and ventricular paced complexes with a right bundle branch block pattern and left axis deviation. The patient׳s post-procedural course was uneventful.