Congenital left ventricular outpouchings: a systematic review of 839 cases and introduction of a novel classification after two centuries

BACKGROUND

Congenital left ventricular outpouchings (LVOs) are reported under five overlapping and poorly defined terms including left ventricular accessory chamber, left ventricular aneurysm (LVA), left ventricular diverticulum (LVD), double-chambered LV, and accessory left ventricle. Diagnostic criteria are frequently mixed and not mutually exclusive. They convey no information regarding treatment strategy and prognosis.

OBJECTIVES

The aim of this systematic review is to provide a clear and inclusive classification, with therapeutic and prognostic implications, for congenital LVOs.

DATA SOURCES

We performed three separate sets of search on three subjects including "congenital left ventricular outpouchings," "important and simply measurable markers of left ventricular function," and "relationship of mechanics of intraventricular blood flow and optimal vortex formation in left ventricle and elliptical geometry of LV."

STUDY ELIGIBILITY CRITERIA

We enrolled case series, review articles, and case reports with literature review. All types of acquired LVO's were excluded.

STUDY APPRAISAL AND SYNTHESIS METHODS

We studied the abstracts of all searched articles. We focused on diagnostic criteria and patients' outcome. To examine the validity and reliability of the novel classification, fifteen previous studies were revisited using the novel classification.

RESULTS

A total of 20 papers from 11 countries fulfilled our inclusion criteria. The age of patients ranged from prenatal age to geriatric age range. Diagnostic criteria were clearly stated only for two of the above five terms (i.e., congenital LVA and congenital LVD). Cases with mixed diagnostic criteria were frequent.Elliptical geometry of left ventricle was found to have significant impact on effective blood flow mechanics in LV. A simple inclusive classification for congenital LVOs, with therapeutic and prognostic implications, was introduced.

CONCLUSION

The cornerstone of this classification is elliptical LV geometry. Large-type IIc LVO have dismal prognosis, if left untreated. LVO type I and small LVO type IIa have the best prognosis.

A case of left ventricular aneurysm caused by localized myocardial infarction

A 73-year-old man was hospitalized for unstable angina pectoris with no history of myocardial infarction. After undergoing percutaneous coronary intervention, left ventriculography incidentally revealed a cavity in the anterior wall, and echocardiography found the cavity wall to be dyskinetic. Myocardial contrast echocardiography revealed that the wall of the cavity was surrounded by myocardial tissue with low perfusion. Furthermore, radial strain in the wall of the cavity was low. Myocardial scintigraphy showed a localized defect on the anterior wall. The patient was finally diagnosed as true aneurysm after asymptomatic and localized myocardial infarction, and has since been followed up by echocardiography in the outpatient clinic.

[Congenital left ventricular aneurysm in a 17-year-old competitive athlete]

We present the case of a 17-year-old competitive athlete with an asymptomatic left ventricular aneurysm (LVA). Echocardiography demonstrated hypoplasia of the septum and a large apical LVA. Magnetic resonance imaging (MRI) detected a very thin and fibrotic wall of the LVA. Due to the potential risk of rupture the LVA was surgically resected and the apex of the left ventricle was covered with a patch plasty. The patient had an event-free postoperative course. Because of the potential risk of arrhythmia, the patient was recommended not to participate further in competitive sport.