Cardiac magnetic resonance imaging in Holmes’ heart: Decoding a rare variant of double-inlet left ventricle

Abstract

Holmes’ heart, a rare variant of double-inlet left ventricle with rudimentary right ventricle and ventriculoarterial concordance, predisposes to pulmonary overcirculation and heart failure due to unrestricted shunting. We report the case of a 32-year-old male, in whom cardiac magnetic resonance (CMR) revealed Holmes’ heart with marked pulmonary artery dilation and advanced heart failure after long-term clinical management. This case highlights the value of CMR in characterizing complex anatomy and reinforces the importance of early surgical palliation to prevent late decompensation.

INTRODUCTION

Double-inlet left ventricle (DILV) is a rare congenital heart malformation, in which both atria predominantly connect to a morphologically left ventricle (LV). This anomaly may coexist with a rudimentary right ventricle, which lacks a complete inflow component but often contributes trabecular or outlet portions.[1,2] The ventriculoarterial connection is variable: Discordant in approximately 58% of cases, concordant in 21%, double-outlet right ventricle in 11%, double-outlet LV in 5%, and single-outlet in 5%.[1] The combination of DILV with a rudimentary right ventricle and ventriculoarterial concordance corresponds to the Holmes’ heart, originally described by Andrew Holmes in 1823.[2] Morphological studies have shown that Holmes’ hearts typically present with two atrioventricular valves – usually with mitral morphology (71%) – or, less frequently, with a common atrioventricular valve (29%).[2] Although most patients with DILV undergo staged palliation culminating in the Fontan procedure, some cases remain untreated, particularly when surgical intervention is deferred or refused.

CLINICAL SUMMARY

A 32-year-old male with a known history of congenital heart disease under long-term follow-up was referred for cardiac magnetic resonance (CMR) imaging due to symptoms of heart failure. The CMR study demonstrated a DILV with a rudimentary right ventricle located on the right side [Figure 1] and ventriculoarterial concordance [Figure 2]. Additional findings included a nonrestrictive ventricular septal defect [Figure 3] and marked dilation of the pulmonary arteries [Video 1]. The atrioventricular connections were established through two discrete valves, and there was mild systolic dysfunction [left ventricular ejection fraction of 43%, Video 2]. Given the absence of prior palliative surgery, management had remained exclusively clinical, as the patient’s family declined surgical intervention during childhood. The patient currently exhibits features of advanced heart failure, reflecting the hemodynamic burden of longstanding pulmonary overcirculation.

Figure 1.

Four-chamber view cine magnetic resonance imaging in different planes (a and b) demonstrate usual atrial arrangement (right atrium [RA] on the right, and left atrium [LA] on the left), ventricular D-loop (rudimentary right ventricle on the right, and dominant left ventricle [LV] on the left), and univentricular biatrial atrioventricular connection (RA and LA connected to the LV)

Figure 2.

The right ventricular outflow tract plane, (a) depicts the pulmonary artery connection to the right ventricle and the left ventricular outflow tract plane, (b) shows the connection between the aorta and the left ventricle, in keeping with a concordant ventriculoarterial connection

Figure 3.

Right ventricular outflow tract plane showing the ventricular septal defect

DISCUSSION

The Holmes’ heart is a distinctive variant within the spectrum of DILV. It is defined by the presence of two atrioventricular valves connected to a morphologically LV, a rudimentary right ventricle, and ventriculoarterial concordance.[2] Morphological analyses confirm that the rudimentary right ventricle is typically right-sided (86%), lacks a complete inlet, and supports the pulmonary trunk via an outlet component.[2] Recognition of this entity is crucial, as its physiology differs from other DILV variants: Unrestricted interventricular communication and ventriculoarterial concordance predispose to pulmonary overcirculation and congestive heart failure, in contrast to cases with outlet obstruction, which may mimic tetralogy of Fallot.[1,2]

From a historical standpoint, Holmes described his case as “intermediate between double and single hearts,” foreshadowing debates on terminology that persist today. Although often grouped under the umbrella of “single ventricle” or “univentricular heart,” detailed morphologic studies emphasize that these patients retain two ventricular chambers, albeit asymmetrically developed.[2] Abandoning the term “single ventricle” in favor of a descriptive diagnosis such as DILV with rudimentary right ventricle and ventriculoarterial concordance provides greater clarity and avoids conceptual pitfalls.[1]

The clinical course of Holmes’ heart is determined primarily by the size of the interventricular communication and the presence or absence of outflow obstruction.[2] In patients with a large defect and concordant great arteries, as in our case, the dominant physiology is excessive pulmonary blood flow, resulting in progressive ventricular dilation, pulmonary hypertension, and eventual heart failure. Without surgical intervention, long-term outcomes are poor, although supportive therapy may provide temporary stabilization. Surgical options for DILV include two main strategies: Fontan palliation, which routes systemic venous return directly to the pulmonary arteries, and ventricular septation, which attempts anatomic correction in selected cases.[1] Morphological studies suggest that Holmes’ hearts, due to their unobstructed atrioventricular valves and ventriculoarterial concordance, may be well suited for the Fontan procedure.[1,2] Nevertheless, surgical results depend on multiple factors, including the adequacy of pulmonary arteries, atrioventricular valve morphology, and conduction system anatomy. In the present case, surgical palliation was declined during childhood, precluding intervention at the optimal window and leaving the patient susceptible to progressive decompensation.

CONCLUSION

Holmes’ heart, the rare combination of DILV with rudimentary right ventricle and ventriculoarterial concordance, represents a distinct morphologic and clinical entity within the spectrum of univentricular hearts. Unlike DILV with discordant connections or outlet obstruction, Holmes’ heart typically manifests with pulmonary overcirculation and heart failure due to unrestricted shunting. CMR offers a comprehensive evaluation of anatomy and pulmonary artery remodeling, reinforcing its pivotal role in longitudinal management. This case underscores the importance of early recognition and timely surgical palliation, as clinical management alone carries a high risk of progression to advanced heart failure.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.