Journal of Cardiovascular Echography

CASE REPORT
Year
: 2018  |  Volume : 28  |  Issue : 2  |  Page : 133--137

Chronic severe mitral regurgitation with normal left ventricular size – A case with coexisting atrial septal defect


Sami Nimer Ghazal 
 Department of Internal Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia

Correspondence Address:
Sami Nimer Ghazal
Department of Internal Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, P. O. Box 1982, Dammam 31441
Saudi Arabia

Abstract

Severe chronic mitral regurgitation (MR) is known to cause left ventricular volume overload and subsequently left ventricular dilatation. Here, we present a case of a 68-year-old man with severe chronic MR which happened to coexist with atrial septal defect of secundum type leading to the right ventricular dilatation.



How to cite this article:
Ghazal SN. Chronic severe mitral regurgitation with normal left ventricular size – A case with coexisting atrial septal defect.J Cardiovasc Echography 2018;28:133-137


How to cite this URL:
Ghazal SN. Chronic severe mitral regurgitation with normal left ventricular size – A case with coexisting atrial septal defect. J Cardiovasc Echography [serial online] 2018 [cited 2021 Dec 1 ];28:133-137
Available from: https://www.jcecho.org/text.asp?2018/28/2/133/232568


Full Text



 Introduction



Mitral regurgitation (MR) being the most common moderate-to-severe valvular heart disease in the US adult over the age of 55,[1] put a great emphasis on understanding the pathophysiology of the disease. Chronic severe MR has been long known for exerting a volume overload effect on the left ventricle (LV). Therefore, related guidelines have put a great emphasis on LV size for evaluation of MR severity along with the timing for intervention. A rare presentation is described with a unique indication for mitral valve intervention.

The 2017 American Society of Echocardiography recommendations for noninvasive valvular states that LV and left atrium (LA) sizes should be integrated into the grading of MR severity and normal sizes make primary chronic severe MR unlikely.[2] The 2014 American Heart Association/American College of Cardiology guideline for the management of patients with valvular heart disease has LV end-systolic dimension cutoff value of 40 mm for intervention for primary asymptomatic MR and was given a class IB.[3] Our case is a patient with chronic severe primary MR and normal LV and LA sizes.

 Case Report



This is a 68-year-old man who is not known to have any chronic medical illness before presented to our emergency department with a 3 months history of exertional shortness of breath which is progressively worsening over the past 2 weeks. Physical examination revealed blood pressure 130/78 mmHg, heart rate 76 bpm, and respiratory rate of 20/min. The elevated jugular venous pressure was also noted. Cardiac auscultation revealed soft S1, loud P2, left-sided S3, and pansystolic murmur grade 3/6 heard best at the apex. Chest examination revealed basal inspiratory crackles. The patient was admitted to cardiac care unit as a case of heart failure with significant MR for further workup and treatment.

Echocardiography findings

In the transthoracic study, a flail posterior leaflet was noted in the left parasternal long-axis view with anteriorly directed regurgitant jet and normal LV and LA sizes [Figure 1]. The right ventricle (RV) and right atrium (RA) are severely dilated [Figure 2]a and [Figure 2]b. There is a moderate tricuspid regurgitation with pulmonary artery hypertension with a peak tricuspid regurgitation gradient of 50 mmHg and an estimated pulmonary artery systolic pressure of 60 mmHg [Figure 2]c and [Figure 2]d. Parasternal short-axis view demonstrated D-shape septum during diastole but not during systole indicative of RV volume overload [Figure 2]d.{Figure 1}{Figure 2}

Transesophageal echocardiogram was performed for better assessment of the MR and the etiology of RV dilatation and volume overload.

Mid esophageal view at 0° showed a flail P2 scallop with anteriorly directed jet and normal size LV and LA while severely dilated RV and RA were noted [Figure 3]. Three-dimensional (3D) acquisition of the mitral valve with enface view from LA side (surgical view) confirmed a flail P2 scallop [Figure 4]. A secundum atrial septal defect (ASD) was seen on further images with the flail mitral leaflet pointing toward the ASD with predominantly left to the right shunt [Figure 5].{Figure 3}{Figure 4}{Figure 5}

The patient has two pathologies on echocardiography that need to be graded for the purpose of management plan. MR quantification was not possible utilizing the proximal isovelocity surface area method as the jet is very eccentric and no proper flow convergence zone could be identified. Volumetric method for MR assessment was performed. Mitral annular area was calculated by measuring the annular diameter and assumption of a circular annulus as well as direct 3D planimetry which yielded similar results [Table 1]. Mitral valve stroke volume was then calculated to be 70 ml [Figure 6]. LV stroke volume was calculated to be 27 ml, and therefore, the regurgitant volume is 43 ml, and the regurgitant fraction is 61% [Figure 7]. With further probe manipulation MR jet was aligned parallel to the ultrasound beam, and spectral Doppler was obtained making it possible to calculate effective regurgitant orifice area which came to be 0.41 cm2. MR is clearly severe although regurgitant volume did not reach the cutoff value of severe (60 ml) due to shunting and low mitral valve stroke volume, but the regurgitant fraction is very significant.{Table 1}{Figure 6}{Figure 7}

Shunt calculation was made through two different methods for the purpose of confirmation. Right ventricular outflow (RVOT) stroke volume was calculated by area X velocity time integral (VTI), and it was 120 ml [Figure 8] giving a Qp/Qs of 4.4:1. Direct shunt volume calculation was also possible by 3D planimetry of the ASD area multiplied by the VTI obtained at the defect site giving a shunt volume of 90 ml [Figure 9]. By adding shunt volume to the left ventricular outflow tract stroke volume, RVOT stroke is obtained and is 117 ml which gave almost a similar result to the previous method [Table 1].{Figure 8}{Figure 9}

 Discussion



Here, we describe an unusual presentation of severe chronic MR with normal LV and LA sizes but dilated RV and RA due to the left to right shunt at the atrial level. The patient's ASD shunt is significant, and we believe that MR plays a major role in the shunt amount in two different ways. First, by increasing LA pressure, hence, more pressure gradient between LA and RA and therefore, more left to right flow. Second, the MR jet is directed toward the ASD and therefore, directly escapes to RA which explains the normal size LA. Probably, if the patient had a flail anterior leaflet with posteriorly directed jet, i.e., away from the septum or a more central jet, the LA will be dilated as it accommodates more volume. In 1916, Lutembacher, a French cardiologist, described a syndrome composed of ASD secundum and an acquired mitral stenosis where the presence of ASD will vent the LA to RA and decreases the incidence of pulmonary congestion.[4] We describe an unusual presentation which has four components: (1) Severe chronic primary MR, (2) ASD secundum, (3) Normal LV size, and (4) Dilated RA and RV. The importance of this entity recognition is the timing for intervention. We recommend mitral valve intervention and ASD closure just similar to ASD closure indications, i.e., RV dilatation.[5] In case of Eisenmenger syndrome, we still recommend mitral valve intervention without simultaneous ASD closure.

 Conclusion



In case of sizable ASD, severe chronic MR can still present with normal LV and LA sizes. Awareness of the hemodynamics associated with these combinations of pathologies is important as the timing for mitral valve intervention will not be dependent on the LV size and function, the RV size should be the main determinant of intervention instead. Proper quantification of MR is essential in determining the severity especially in this complex pathology since the LV size is deceivingly normal.

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.

Acknowledgment

The author would like to thank Dr. Nasser Alali for his assistance in collecting clinical data.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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