Paroxysmal atrioventricular block as an initial presentation of bicuspid aortic valve calcification: a case report

Figures

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  Figure 1. Electrocardiographic findings upon presentation. (A) Initial 12-lead electrocardiogram showing high-grade AV block with a ventricular escape rhythm, interspersed with brief periods of 1:1 AV conduction. (B) Rhythm strip demonstrating dynamic conduction abnormalities with alternating bundle branch block. The conduction pattern intermittently shifts between left bundle branch block morphology and right bundle branch block morphology associated with left anterior fascicular block. First-degree AV block is also present, suggesting advanced His–Purkinje system involvement and intermittent mechanical compromise of the conduction system. AV, atrioventricular.

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  Figure 2. Transoesophageal echocardiography imaging. The image confirms the presence of a bicuspid aortic valve with fusion of the right and left coronary cusps. A 9-mm oscillating, V-shaped hyperechogenic mass (arrow) is visualized on the septal aspect of the left ventricular outflow tract, contiguous with the heavy calcification of the fused cusps.

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  Figure 3. Cardiac computed tomography findings. (A) Three-dimensional volume-rendered CT image showing a calcified projection arising from the aortic valve apparatus. The blue-coloured structure indicates the segmented calcified spur. (B) Four-chamber reconstructed CT image showing extension of the calcified projection towards the basal membranous septal/left ventricular outflow tract septal region, corresponding to the expected vicinity of the atrioventricular node–His bundle axis. (C) Axial CT image showing the calcified lesion adjacent to the septal aspect of the left ventricular outflow tract. Red arrows indicate the calcified projection.

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  Figure 4. Intraoperative view of the aortic valve and left ventricular outflow tract. (A) Surgical inspection reveals a calcified projection extending into the left ventricular outflow tract. A hypermobile nodular lesion (arrow), suspected to represent thrombotic material, is attached to the apex of the calcified spur. (B) The operative field after resection, showing the debrided surface following removal of the mass and calcified spur. (C) Gross appearance of the excised calcified fragments obtained during surgery. The retrieved specimen corresponds to the calcified lesion identified on preoperative computed tomography imaging.

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  Figure 5. Follow-up electrocardiogram after surgical resection showing normal sinus rhythm without recurrence of atrioventricular block.