PMC9133913_01
Electrocardiogram and myocardial contrast echocardiography. (A) Electrocardiogram at the onset showed complete atrioventricular block with a ventricular escape at a rate of 37 beats per minute. (B) Echocardiogram after pacemaker implantation indicated a ventricular pacing rhythm with a wide QRS complex. (C) Myocardial contrast echocardiography examinations showed homogenous and equal enhancement intensity in the basal, middle and apical segments.
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F1
The electrocardiogram (ECG) showed CAVB with a ventricular escape rate at 37 bpm (Figure 1A), which was normal prior to therapy with combined pembrolizumab. The pacemaker was programmed with DDD pacing mode and ECG recorded a ventricular pacing rhythm with a wide QRS complex (Figure 1B). Myocardial contrast echocardiography showed that the perfusion of myocardium was normal (Figure 1C), with a normal left ventricular ejection fraction (LVEF) of 65%.
Speckle tracking echocardiography, repeat electrocardiogram, and timeline of disease diagnosis and treatment. (A) Global longitudinal strain (GLS) bull's-eye plot showed a slightly decreased GLS of-16.4% and mainly impaired strain in the basal segments of anterior and lateral wall. (B) Electrocardiogram on the 5th day of admission showed sinus rhythm with a normal rate of 69 beats per minute. (C) Timeline of disease diagnosis and treatment. ICI, immune checkpoint inhibitor; CAVB, complete atrioventricular block; IV, intravenous.
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F2
Longitudinal strain was mainly impaired in the basal segments of the anterior and lateral walls (Figure 2A). Excitingly, the patient's symptoms rapidly resolved, and repeat ECG revealed the recovery of atrioventricular conduction (Figure 2B) on the 5th day of admission. The overview of the clinical course of this patient is illustrated in Figure 2C.