case_images: PMC5804611_01
case_images: Preoperative electrocardiogram. The tracing of lead II shows second-degree atrioventricular block with 2:1 AV conduction, ventricular rate of 46 beats per minute. Every other P wave (marked) was regularly conducted. Note the short PR interval during conducted complexes and the narrow QRS complexes
case_images: 40981_2017_99_Fig1_HTML.jpg
case_images: PMC5804611_01_40981_2017_99_Fig1_HTML.jpg
case_images: Fig1
case_images: However, routine preoperative resting 12-lead electrocardiogram (ECG) revealed a second-degree 2:1 AV block with a narrow QRS complex (0.102 s), heart rate (HR) of 46 bpm, normal axis, and with no ischemic change (Fig. 1).
case_images: Intraoperative monitor electrocardiogram following induction of general anesthesia. The traces show complete atrioventricular block with junctional escape rhythm of approximately 30-40 beats per minute. The P waves (marked) were completely dissociated from the QRS complexes. Artifacts most likely due to poor electrode contact with the skin caused the noisy baseline in this tracing
case_images: 40981_2017_99_Fig2_HTML.jpg
case_images: PMC5804611_01_40981_2017_99_Fig2_HTML.jpg
case_images: Fig2
case_images: Conversely, the 2:1 AV block progressively converted to complete AV block (Fig. 2).