Premature Ventricular Complexes With 2 QRS Morphologies

Visual Summary. Preprocedural, Intraprocedural, and Postprocedural Findings in a Patient With Cardiac Crux Premature Ventricular Complexes The visual summary illustrates the diagnostic and procedural workflow. Preprocedural electrocardiography showed 2 alternating premature ventricular complex QRS morphologies, and cardiac magnetic resonance imaging helped localize the suspected target region. Intraprocedural fluoroscopy and electroanatomical mapping demonstrated bilateral endocardial mapping at the right ventricular–coronary sinus junction and the opposite left ventricular site. Postprocedural electrocardiography showed sinus rhythm without recurrent premature ventricular complexes, and cardiac magnetic resonance imaging confirmed discrete ablation lesions near the cardiac crux. CMR = cardiac magnetic resonance; ECG = electrocardiogram; other abbreviations as in Figure 3.

Figure 1. Baseline 12-Lead Electrocardiogram Demonstrating Ventricular Bigeminy With 2 Alternating Premature Ventricular Complex QRS Morphologies The baseline 12-lead electrocardiogram shows frequent premature ventricular complexes in bigeminy with 2 alternating QRS morphologies. Both morphologies have a superior axis, with subtle differences in bundle branch block pattern and precordial transition, suggesting a shared cardiac crux origin with preferential exits.

Figure 2. Coronary Angiography Demonstrating No Significant Coronary Artery Stenosis Coronary angiography performed before the ablation procedure showed no significant obstructive coronary artery disease.

Figure 3. Biventricular Mapping to Identify the Earliest Activation Site of the Premature Ventricular Complexes Bilateral endocardial mapping was performed at the basal inferoseptal region. Mapping from the right ventricular side near the tricuspid annulus and from the opposite left ventricular side near the mitral annulus identified early activation sites for both premature ventricular complex morphologies, supporting a deep cardiac crux substrate with preferential exits. CS = coronary sinus; LAO = left anterior oblique; LV = left ventricle; PVC = premature ventricular complex; RAO = right anterior oblique; RV = right ventricle.

Figure 4. Postablation Electrocardiogram and Follow-Up Monitoring Showing No Premature Ventricular Complex Recurrence The postablation electrocardiogram shows sinus rhythm without recurrent premature ventricular complexes after bilateral endocardial ablation and lesion-depth enhancement.

Figure 5. Cardiac MRI and a Merged 3-Dimensional Electroanatomical Map Showing Discrete Lesions at the Cardiac Crux Preablation and postablation cardiac magnetic resonance images and the merged 3-dimensional electroanatomical map demonstrate discrete ablation lesions at the inferoseptal cardiac crux region, corresponding to the successful ablation sites. EAM = electroanatomical mapping; LGE = late gadolinium enhancement; MRI = magnetic resonance imaging.