Unexpected and fatal hemodynamic collapse during transapical transcatheter aortic valve implantation -A case report-
A 79-year-old man was admitted with severe aortic stenosis. He suffered from chest discomfort on minimal exertion. His medical history included 5-times percutaneous coronary stent insertions for unstable angina, chronic obstructive pulmonary disease, atrial fibrillation, and atherosclerosis obliterans. Pre-procedural echocardiography showed severe aortic stenosis (severe thickened and calcified aortic valve, aortic valve area = 0.72 cm2 , aortic annulus = 22 mm) and mild to moderate aortic regurgitation, moderate tricuspid regurgitation, both atrial enlargement, and concentric left ventricular hypertrophy. However, left ventricular systolic function (ejection fraction = 63%) and right ventricular systolic pressure (28 mmHg estimated by the maximal velocity of tricuspid regurgitation) were in normal range. The estimated logistic Euroscore of the patient was 29.8%. The cardiologists recommended transapical TAVI instead of conventional surgery because the patient was considered as the high-risk population.\nAfter placing an invasive arterial catheter through a brachial artery, anesthesia was induced with intravenous midazolam, etomidate, and rocuronium. It was maintained with sevoflurane and a continuous infusion of remifentanil. A pulmonary artery catheter was placed through right internal jugular vein, and a transesophageal echocargiographic (TEE) probe was inserted. After a left anterior mini-thoracotomy, an angiocatheter was inserted through the apex of the left ventricle. A guidewire was passed through the aortic valve and arch, and the tip was positioned in the abdominal aorta for stability. Following the two times of rapid ventricular pacing (200 beats/min) for 10 seconds, the balloon valvuloplasty was performed. Norepinephrine (0.02-0.05 mcg/kg/min) was continuously infused for maintaining blood pressure and norepinephrine 5 mcg was successively injected twice prior to RVP for balloon valvuloplasty. From anesthetic induction to rapid ventricular pacing, the patient's vital signs were well maintained (systolic blood pressure, 90 to 144 mmHg; diastolic blood pressure, 46 to 70 mmHg; central venous pressure, 7 to 12 mmHg; mean pulmonary arterial pressure, 20 to 22 mmHg; and heart rate, 68 to 110 beats/min). In addition, the mean arterial pressure was also maintained at around 50 mmHg, during rapid ventricular pacing.\nFollowing the balloon valvuloplasty with rapid ventricular pacing, the mean blood pressure dropped to below 40 mmHg and did not recover. At the same time, central venous and the mean pulmonary arterial pressures were raised up to 22 mmHg and 44 mmHg, respectively. TEE showed the severe global hypokinesia. Two minutes after a rapid ventricular pacing, ventricular fibrillation was developed. Several attempts of defibrillation failed to restore the sinus rhythm. Emergent extracorporeal membrane oxygenation (ECMO) device was initiated immediately, through femoral artery and vein. Coronary angiography showed normal coronary arterial flow. After starting the support by ECMO, the patient's hemodynamics became stable. A 26-mm Sapien transcatheter heart valve (Edward Lifesciences, Irvine, CA, USA) was deployed under the ECMO support. TEE and angiography showed merely minimal aortic regurgitation. The patient was transferred to an intensive care unit for further supportive care. However, regardless of the ECMO support and supportive medical treatments, he did not recover from the state of heart failure. Finally, he died from cardiogenic shock and heart failure on post-procedure day 4.