Complete atrioventricular block and infective endocarditis in a patient with hypertrophic obstructive cardiomyopathy

Surgical Management of Hypertrophic Cardiomyopathy Complicated by Infective Endocarditis

BACKGROUND

Infective endocarditis (IE) is a serious complication in hypertrophic cardiomyopathy (HCM). Cardiac surgery is often necessary, however, literature assessing surgical outcomes is limited.

METHODS

From December 1995 to September 2018, 43 patients with a history of HCM and native valve IE underwent cardiac surgery at our institution. Relevant data were abstracted from medical records and analyzed.

RESULTS

Median age was 57 years (IQR 45-67), 81% (n=35) were male. IE was active in 21% (n=9) patients at the time of surgery; Of these, the suspected origin of infection was orodental in 19% (n=8) patients. Significant mitral valve regurgitation was detected in 54% (n=23) patients and aortic valve regurgitation in 7% (n=3). Septal myectomy (SM) was performed in 95% (n=41) patients, with concomitant valve surgery in 58% (n=25) including prosthetic replacement in 28% (n=12). Two patients underwent double valve replacement without SM. Outflow gradients improved from median 67mmHg (IQR 34-97 mmHg) to 9mmHg (IQR 6-22 mmHg). One in-hospital death occurred due to uncontrollable pulmonary edema. As of last follow up, seven patients required reoperation and the 5 and 10-year cumulative incidences were 11% and 26%. Ten deaths occurred and overall survival probability at 5 and 10-years was 94% and 78% respectively.

CONCLUSIONS

Valvular complications of IE add complexity to surgical management of HCM. There is an increased need for concomitant valve repairs, prosthetic replacements and reoperation. These data underscore the need for recognition of infection, especially after oral procedures, which preceded majority of the active IE cases.

Infective Endocarditis with Intermittent Atrioventricular Block and Pseudoaneurysm of the Mitral-aortic Intervalvular Fibrosa in a Patient with Severe Aortic Stenosis

Atrioventricular (AV) block and pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) are rare complications of infective endocarditis (IE). A 72-year-old man with severe aortic stenosis was hospitalized due to IE. After admission, intermittent AV block and P-MAIVF were noted. Interestingly, an accelerated junctional rhythm was observed during the process of AV block resolution. Elective surgery, which included patch closure of the fistula and replacement of the aortic valve, was successfully performed. The patient has remained in good condition without the recurrence of AV block. This case report describes a rare comorbidity of AV block and P-MAIVF in a patient with aortic valve IE.

Infective Endocarditis Presenting as Complete Heart Block With an Unexpected Finding of a Cardiac Abscess and Purulent Pericarditis

Intracardiac abscess resulting in complete heart block is an infrequent complication of infective endocarditis. Most presentations of endocarditis are limited to valvular and perivalvular structures, with varying degrees of heart block occurring in the minority of cases. We report a case of endocarditis manifesting as chest pain associated with ST segment elevation and complete heart block. The patient expired unexpectedly within a few hours of presentation. Postmortem examination revealed an atrial septal abscess, purulent pericardial collection, and fibrinous pericarditis. Spread of the abscess into the atrial septum was postulated to be the cause of the complete heart block. In endocarditis, the ominous development of heart block and a poor response to antibiotic therapy imply significant extension of the infection. Management therefore requires prompt ventricular pacing with consideration for valve replacement and possible pericardial drainage.