The relationship between new cardiac conduction defects and extension of valve infection in native valve endocarditis

Abstract

Summary: New conduction defects in the setting of native valve infective endocarditis (IE) are commonly believed to be associated with direct extension beyond the free valve area. At University Hospital in Newark, among 100 cases of IE, in none of five instances of associated conduction defects (excluding first-degree heart block) was this the case. In neither of two instances of direct extension of valve infection was this accompanied by a new conduction defect. To explore this relationship, autopsy, surgical, and echocardiographic findings from other institutions were combined with these data. Among 47 instances of new conduction defects in IE, only 60% could be related to direct extension of valve infection. The cause was coronary embolization in 4% and unknown in 36%. Among 119 cases of complicated valve lesions, significant conduction defects were documented by ECG in only I5 % . In IE the appearance of new conduction abnormalities may often result from causes other than extension of valve infection. Furthermore, complicated valve lesions may often be present without electrocardiographic evidence, indicating interruption of normal conduction path ways.

Patient Selection Criteria and Management Guidelines for Outpatient Parenteral Antibiotic Therapy for Native Valve Infective Endocarditis

“…Evaluation for perivalvular extension is warranted for patients with persistent fever or bacteremia, new valvular murmur or insufficiency, recurrent emboli, or fixed conduction defects seen on electrocardiograms [70]. The sensitivity of electrocardiogram for perivalvular extension is only 27%-83% [70,74,78,79], and the negative predictive value of a normal electrocardiogram is not known [70]. Transesophageal echocardiography has dramatically improved detection of perivalvular abscess, with a sensitivity of 87% and a specificity of 95%, compared with a sensitivity of 28% and a specificity of 99% for transthoracic echocardiography [80].…”

A Rare Complication of Infective Endocarditis

“…According to the literature, the development of cardiac conduction abnormalities (CA), particularly AVB, has a high positive predictive value for abscess formation but a low sensitivity (9). A new AVB has an overall positive predictive value of 66%, a specificity of 89%, and a sensitivity of 28% to 45% for identifying perivalvular extension in patients with IE (6,8). In our case, the diagnosis was delayed because mild fever and first degree AVB was not evaluated as a predictor of infective endocarditis.…”

“…Atrioventricular block is potentially the result of the extension of infection from the valve leaflets into the surrounding myocardium or anatomical destruction of adjacent conduction tissue by the abscess formation (7,8). The degree of AVB varies with the extended effect of IE on conducting system.…”

Complete Heart Block Associated With Mitral Annular Abscess

“…2 New atrioventricular block has an overall positive predictive value of 66%, a specificity of 89%, and a sensitivity of 28% to 45% for underlying perivalvular extension. 5 Transthoracic echocardiography has a sensitivity of 18% to 60%, whereas TEE has a sensitivity of 76% and a specificity of 94% for detecting perivalvular extension. 2 Therefore, TEE should be considered when there is a high clinical index of suspicion and when results are normal on 2-dimensional transthoracic echocardiography.…”

“…2 Other authors suggest a more aggressive approach, in which all patients with MEN 1/ZES, regardless of tumor size or results of imaging or endoscopic studies, undergo exploratory laparotomy. 1,5 This is an area of controversy that both we and Drs Truty and Thompson highlight. Further research, including long-term prospective studies with sufficient numbers of patients 2 that include assessments of novel risk factors such as those that link genotypephenotype relationships with tumor aggressiveness in MEN 1/ ZES 4 should help address this controversy.…”