Remember me
CASE REPORT
Year : 2022 | Volume
: 32
| Issue : 3 | Page : 165-167
Severe mitral regurgitation following partial rupture of papillary muscle: The role of intraoperative transesophageal echocardiography
Christos Chamos, Paul Balfour
Department of Anesthesia, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
Correspondence Address:
Christos Chamos
Flat 41, Highlands Heath, Portsmouth Road, SW15 3TX, London
United Kingdom
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/jcecho.jcecho_7_22
Papillary muscle rupture (PMR) is an uncommon mechanical complication of myocardial infarction which warrants timely diagnosis and urgent surgical intervention to maximize survival chances. Echocardiography is an essential diagnostic tool, whereas transesophageal echocardiography can provide accurate diagnosis and guide decision-making. We hereby present the case of a patient with partial PMR that presented for cardiac surgery in our institution, with the respective intraoperative echocardiographic findings.
Keywords: Mitral regurgitation, papillary muscle rupture, transesophageal echocardiography
Papillary muscle rupture (PMR) is an uncommon yet potentially lethal complication of acute myocardial infarction (MI). PMR can be complete or partial, affecting either papillary muscle (PM). Urgent surgical intervention is indicated to maximize survival.[1] Intraoperative transesophageal echocardiography (TEE) can provide an accurate diagnosis of the condition and guide decision-making. We hereby present the echocardiographic findings of a patient with partial PMR that presented for surgery in our institution.
Case ReportAn octogenarian male was admitted for a coronary angiogram following a recent non-ST elevation MI, which showed severe ostial left anterior descending (LAD) and circumflex coronary disease. As the coronary anatomy was unsuitable for percutaneous coronary intervention, he was referred to the cardiac surgical team for consideration of surgery.
Overnight, he developed respiratory failure, requiring intubation and mechanical ventilation, together with refractory hypotension. An electrocardiogram demonstrated ischemic changes in the posterior, lateral, and inferior leads, whereas a transthoracic echocardiogram (TTE) identified a flail anterior mitral valve leaflet (AMVL) resulting in torrential mitral regurgitation (MR). An intra-aortic balloon pump was inserted to improve the patient's hemodynamic condition. Following surgical review, a decision for emergency surgery was made.
Intraoperative two-dimensional (2D) TEE showed a flail AMVL with an echo-dense structure suspicious for a PM attached to its tip [Figure 1]. Color flow Doppler (CFD) revealed severe eccentric MR with a jet directed posteriorly across the wall of the left atrium (LA) [Video 1]. In an en face three dimensional (3D) “zoom” view of the mitral valve (MV), the echodensity was visualized and attached to the A2 segment [[Figure 2] and Video 2]. Another echo-dense structure seen in the apex of the left ventricular (LV) was initially diagnosed as a thrombus [Figure 3] but was subsequently correctly identified as an intact, noninfarcted, head of the anterolateral PM.
Figure 1: Two-dimensional transesophageal echocardiogram midesophageal five-chamber view demonstrating a ruptured head of the anterolateral papillary muscle attached to a flail anterior mitral valve leaflet
Figure 2: Three-dimensional transesophageal echocardiogram en face focused wide sector (“zoom”) view of the mitral valve demonstrating a ruptured head of the anterolateral papillary muscle attached to the A2 segment of the anterior mitral valve leaflet
Figure 3: Two-dimensional transesophageal echocardiogram midesophageal five-chamber view demonstrating the ruptured head of the anterolateral papillary muscle attached to a flail anterior mitral valve leaflet, and the intact head of the anterolateral papillary muscle appearing as an apical left ventricular massThe first obtuse marginal branch of the circumflex artery and the LAD were bypassed with segments of the saphenous vein. Inspection of the MV revealed a flail AMVL with one head of the anterolateral PM attached to the tip. The MV was replaced with a 29 mm Perimount Magna Mitral Ease bioprosthesis (Edwards Lifesciences, Irvine, CA), while the posterior leaflet was preserved. The tricuspid valve was repaired with a 30 mm physio ring (Edwards Lifesciences, Irvine, CA). Separation from cardiopulmonary bypass (CPB) was straightforward on low-dose inotropic support, whereas hemostasis was prolonged.
Post-CPB TEE showed a well-functioning mitral bioprosthesis with mild central regurgitation, whereas a new intracavity echodensity was identified in the subvalvular area. This likely represented rupture of the residual head of the PM previously seen in the LV apical area [[Figure 4] and Video 3]. As there were no signs of interference with the prosthetic valve function or LV outflow tract (LVOT) obstruction, it was decided that no further intervention was needed.
Figure 4: Two-dimensional transesophageal echocardiogram midesophageal long-axis view demonstrating the residual, previously intact, head of the anterolateral papillary muscle appearing in the mitral subvalvular areaFollowing the conclusion of the procedure, the patient's chest was left open due to difficulty in achieving hemostasis. During his intensive care unit stay, the patient developed multiorgan failure and passed away 6 days later.
DiscussionPMR is a rare mechanical complication of MI, with an estimated incidence of 0.5%,[2] and is associated with significant mortality, in excess of 50%.[1] Although it can affect either PM, the posteromedial PM is more frequently involved,[3] due to a singular blood supply from the posterior descending coronary artery branch. Moreover, the rupture can present as complete or partial in equal frequency,[4] the latter condition only affecting some of the PM heads as opposed to the entire structure.
Due to its ease of access, echocardiography remains the most commonly used tool for diagnosis. TTE or TEE assessment can help with the visualization of the ruptured PM as well as identification of the flail MV segments.[5] Typically, TTE is undertaken first, with the ruptured PM presenting as an echodensity of varying size and shape[6] which often prolapses into the LA during ventricular systole in a characteristic to-and-fro motion that differentiates it from other masses [Figure 1].
TEE provides superior imaging of the MV, with higher sensitivity compared to TTE,[4] due to the proximity of the probe to the interrogated structure and will often establish the diagnosis when the TTE findings are ambiguous.[7] Further to the depiction of the ruptured PM, 2D TEE can also assist with the precise identification of the affected MV segments,[5] which can then be accurately delineated by 3D imaging. Moreover, TEE will provide additional findings such as the identification of an intact PM head still attached to the LV wall [Figure 2], which will point toward the diagnosis of partial PMR. To the best of our knowledge, this finding has not been reported so far in the existing body of literature in the context of ruptured PM. There is another reported case where a PM head resembled LV thrombus on TEE, but this was in the context of MV replacement.[8] In light of this unique finding, it is reasonable to consider the possibility of partial PMR in the differential diagnosis of an intracavity LV mass, in the presence of concomitant MR.
CFD allows the quantification of the degree of MR by means of the size and direction of the regurgitant jet. The eccentric jet trajectory, away from the flail leaflet, indicates severe MR and is highly suggestive of partial PMR.[4] Due to the anatomy of the mitral valvular apparatus (with both the anterior and posterior leaflets having attachments to both PM), rupture of either PM can result in flail of either MV leaflet. Therefore, the direction of the MR jet cannot reliably predict the PM involved. In addition, CFD will permit an evaluation of the surgical result and will rule out complications such as significant obstruction of the LVOT by the residual head of the PM [Video 3]. Finally, 3D echocardiography can add value and complement 2D imaging of the MV, permitting a precise localization of the prolapsing leaflet scallops and the visualization of the ruptured PM heads.[7],[9],[10]
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
Comments (0)