Brief Case Description
The patient is a 65 year-old male who presented with symptoms of congestive heart failure (CHF). He has a past medical history of hypertension, diabetes, hyperlipidemia, and prior myocardial infarction. Physical examination was remarkable for apical systolic murmur of mitral regurgitation. He underwent a stress test which revealed inferior and inferolateral scarring.
Transthoracic echocardiography (TTE), parasternal long axis and four chamber views, showed systolic restricted motion of both anterior and posterior mitral leaflets (Type IIIb dysfunction). Doppler echocardiography showed a central jet with mild to moderate mitral regurgitation. Quantitative measurement revealed a regurgitant orifice area of 18 mm2 and a regurgitant volume of 27 mL. Pisa radius was calculated at 0.6 cm. Left ventricular end diastolic diameter was 6.8 cm and left ventricular ejection fraction was 27%.
A TTE performed one month earlier in another institution showed severe mitral valve regurgitation and moderate tricuspid regurgitation.
Cardiac catheterization showed severe three vessel coronary artery disease: proximal left anterior descending artery 95% and mid 90% stenosis, proximal left circumflex 80% stenosis with mutiple lesions involving obtuse marginals, proximal right coronary artery 70% stenosis with mid total occlusion. Pulmonary artery pressure was 50/22 mmHg. Cardiac output and index were 3.8 L/min and 1.9 L/min/M2 respectively.
The patient was referred for coronary revascularization and reconstructive mitral and tricuspid valve surgery.
Intraoperative Transesophageal Echocardiography (TEE)
Intraoperative transesophageal echocardiography confirmed the diagnosis of type IIIb mitral valve dysfunction (mid esophageal long axis and four chamber views). Mid esophageal long axis view with color Doppler interrogation of the mitral valve showed mild (2+) regurgitation with a central jet. Left ventricular ejection fraction was calculated at 18%.
Coronary Artery Bypass Grafting (CABG)
The patient underwent coronary artery bypass grafting with the left internal mammary artery to the left anterior descending artery and saphenous vein graft from the aorta to the second obtuse marginal and posterior descending artery (PDA) branches.
Mitral Valve Analysis
Following the exposure of the mitral valve, we first confirmed the echocardiographic findings by observing a tethering of both anterior and posterior mitral leaflets. The mitral annulus was asymmetrically dilated.
Following echocardiographic and operative valve analysis, we can summarize the pathophysiological triad as follows:
Etiology: Ischemic mitral valve disease
Lesions: papillary muscle displacement with leaflets tethering, and secondary annular deformity
Dysfunction: Type IIIb
The patient underwent an undersized remodeling mitral annuloplasty with the implantation of a size 24 mm Carpentier Edwards Physio ring. The prosthetic ring was downsized by two sizes. The patient also underwent a tricuspid remodeling annuloplasty with a 28 mm Carpentier Edwards Classic ring for type I dysfunction.
Postbypass Transesophageal Echocardiography
Mid esophageal four chamber view showed the mitral valve with good leaflet coaptation. Mid esophageal four chamber and long axis views with color Doppler interrogation showed a competent mitral valve with no residual regurgitation.
The postoperative course was uneventful and the patient was discharged home on postoperative day eight.
At 3 years, the patient was doing well and was in NYHA class I-II. TTE showed a competent mitral valve with no recurrent mitral regurgitation (parasternal long axis and four chamber views). The mean transmitral gradient was 3 mmHg. Left ventricular size has decreased with an end diastolic diameter of 4.9 cm while left ventricular systolic function has improved with an ejection fraction of 43%. There was only minimal tricuspid regurgitation.
Cardiac catheterization showed all grafts were patent.