Post-infarction VSD remains an infrequent but devastating complication of atherosclerotic coronary disease. The incidence of this complication has significantly decreased to < 1% of cases with the advent of early reperfusion strategies and adjunct medical therapy [1]. Data on the impact of primary percutaneous coronary intervention and the incidence of VSD are limited. According to Yip et al. [2] primary PCI has a significant impact on the incidence of this complication. The prognosis of post-AMI VSD is very poor, with mortality rates reaching 47% even with intervention in the elderly population [3]. Furthermore, complex forms of ventricular septal rupture with right ventricle involvement and onset of cardiogenic shock are critical prognostic factors [4].
When a ventricular septal rupture complicating acute myocardial infarction is suspected, transthoracic and/or transesophageal echocardiography at patient bedside is the test of choice for early diagnosis and therapy guidance. For this purpose, unconventional transthoracic and subcostal echocardiographic views with color flow doppler mapping to detect the site of septal rupture and visualize right ventricular free wall are mandatory. Unfortunately the acquisition of quality images is challenging and often impossible in recumbent haemodynamically unstable patients with mechanical support. The lack of parasternal window in our case triggered further difficulties for accurate transthoracic echocardiographic diagnosis. 2D TEE allows visualization of the ventricular septum from multiple orthogonal planes; however, it requires a mental 3D reconstruction to better understand the relationship between the defect and the surrounding structures. The introduction of three-dimensional echocardiography offers new imaging possibilities with precise localization and easier definition of the defect anatomy. It provides unique en-face views of the ventricular septum from both left and right ventricular sides [5]. New developments of the 3D matrix array probe allow real-time 3D imaging with high resolution. So, 3D TEE offers additional special information in VSD disease without extending examination time, permits quantitative recording of septal defect dynamics and enhances the understanding of complex cardiac anatomy and hemodynamics. It is a potentially valuable clinical tool for diagnosing and managing patients with VSD [6]. Cheng et al. [7] reported an excellent correlation in measuring the size of VSD by 3D echocardiography compared with intraoperative evaluation.
The management of PIVSD consists of surgical repair and/or percutaneous closure. Limited by the size with the largest device available being 24-mm in diameter, the percutaneous occluder closure is attractive in conditions of small VSD (<15 mm) and/or patients being poor surgical candidate [8]. Sporadic case reports suggested that percutaneous occluder devices could be implanted for the purpose of bridging to surgical repair [9]. Nevertheless, the fragility of infarct myocardium in acute setting is the major challenge for open repair and transcatheter closure. Even though the timing for intervention is a debating issue, it’s generally accepted that, if the patient’s status allows, intentional deferment of intervention by 3 to 4 weeks will facilitate surgical repair and reduce the risk of residual shunt by tissue healing. In our case, the size of VSD (38 mm) measured by 3D TEE excluded the feasibility of percutaneous closure procedure. Hence, we adopted the strategy of mechanical support prior to and following surgical repair. Pre-operative mechanical support allowed stabilizing the patient’s hemodynamics, unloading the ventricles and decreasing the left-to-right shunt as well as consolidating the infarct tissue through fibrous scar formation; post-operative mechanical assist facilitated the tissue healing and reduced the risk of residual shunt as ECMO led to ventricular pressure and volume unloading that reduced the wall stress and suture tension.
Our successful experience in the management of this challenging case demonstrates the therapy-guiding values of 3-D TEE in the management of PIVSD, as precise preoperative anatomical assessment of PIVSD is essential to determine the therapeutic strategy. Our algorithm of management of PIVSD is to perform thorough echocardiographic exams at first, if the size < 15 mm and the unfavorable anatomical characteristics such as frail rim tissue and papillary muscle involvement are excluded, percutaneous closure can be thereafter performed as a definitive treatment or bridge to surgical repair; in other cases, pharmacological and/or mechanical support for at least 1 week is adopted before surgical repair.