Cardiac Resynchronization Therapy in Situs Inversus Totalis and Congenitally Corrected Transposition of Great Arteries

Figures

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  Figure 1. Baseline Cardiac Computed Tomography Angiogram This shows the cardiac anatomy {I,D,D} with atrial situs inversus (left atrium [LA]) on right side {I}, dextro-loop with systemic right ventricle (RV) on right side {D}, and aorta (Ao) to right (dextro) of pulmonary artery (not seen) {D}. The descending Ao is right sided. Implantable cardioverter-defibrillator (ICD) lead is seen in the subpulmonic left ventricle (LV).

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  Figure 2. CRT Implant Procedure Top panels show contrast venography of the coronary venous system. The coronary sinus (CS) is directed to the right of the body with a lateral vein draining the free wall of the systemic right ventricle. Bottom panels show the cardiac resynchronization therapy (CRT) lead implanted in the superior branch of the lateral vein. Preexisting right atrial (RA) and ICD leads are also shown. LAO = left anterior oblique; RAO = right anterior oblique; other abbreviations as in Figure 1.

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  Figure 3. Chest Radiography Showing the CRT-D Leads (A) (Posteroanterior projection): This demonstrates dextrocardia with the pulse generator in the left chest, and the leads coursing through the left superior vena cava with the CRT lead on the right lateral wall of the heart (systemic right ventricle). (B) (Lateral projection): CRT-defibrillator, note is made of the previously placed RA and ICD leads with both tips directed posteriorly. Abbreviations as in Figure 2.

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  Figure 4. Baseline and Postprocedural ECG Top panel shows pre-cardiac resynchronization therapy electrocardiography (ECG) demonstrating atrial sensed ventricular paced rhythm with QRSs generated from single-site pacing from implantable cardioverter-defibrillator lead in subpulmonic left ventricle (QRS duration 218 milliseconds). The QRS vector is directed right (negative lead I) and superior (negative lead aVF). Bottom panel shows post-cardiac resynchronization therapy ECG demonstrating sequential atrial biventricular paced rhythm with QRS duration 132 milliseconds and reduced QRS amplitude (cancellation of forces). QRS axis is left (positive I) due to contribution of pacing from lateral systemic right ventricle.