1. Cleft mitral valve without ostium primum defect: anatomic data and surgical considerations based on 41 cases 
Stella Van Praagh, MD, Diego Porras, MD, Guido Oppido, MD, Tal Geva, MD, Richard Van Praagh, MD 
The Annals of Thoracic Surgery 
Volume 75, Issue 6, Pages (June 2003)
DOI: /S (03)00167-X

2. Fig 1
Left ventricle of girl, aged 6 years 10 months, with normally related great arteries (case 1, Table 1). Ventricular septum is intact. Mitral valve (MV) cleft attaches to membranous septum, which is under commissure between right coronary cusp (RCC) and noncoronary cusp (NCC) of aortic valve. Absence of ventricular septal defect results in semivertical direction of MV cleft toward left ventricular outflow. Margins of MV cleft are thickened and rolled. Anterolateral papillary muscle (ALPM) and posteromedial papillary muscle (PMPM) of MV are hypertrophied and close together. Left ventricular inlet/outlet ratio = 0.8.
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

3. Fig 2
Left atrial and left ventricular view of heart of girl, aged 12 years 8 months, with normally related great arteries (case 2, Table 1). Mitral valve (MV) cleft is very wide with rolled, thickened margins. Cleft attaches to the intact membranous septum. Left atrium is enlarged and receives right pulmonary veins (RtPVs) and left pulmonary veins (LtPVs). Atrial septum is intact. Left ventricle (LV) is markedly hypertrophied. Left ventricular inlet/outlet ratio = 0.8. (MPA = main pulmonary artery; Septum 1° = septum primum.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

4. Fig 3
Heart of 23-year-old woman (case 10, Table 1) with tetralogy of Fallot and ventricular septal defect (VSD) extending into area of membranous septum. (A) Right atrial and right ventricular view. (B) Opened left ventricle. Left ventricle inlet septal length is shorter than that of outlet (0.675). Mitral valve (MV) cleft attaches to inferoposterior crest of the VSD. Plane of cleft is perpendicular to plane of ventricular septum. Posteromedial papillary muscle (PMPM) is larger than anterolateral papillary muscle (ALPM), corresponding to larger size of posterior segment of anterior mitral valve leaflet. Distance between the two papillary muscle groups is shorter than normal. The margins of cleft are thickened and rolled, indicative of mitral regurgitation. (AoV = aortic valve; CoS = coronary sinus; EV = Eustachian valve; FO = fossa ovalis; TV = tricuspid valve.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

5. Fig 4
Heart and part of lungs of 2-month-old girl with tetralogy of Fallot (case 7, Table 1). Mitral valve (MV) cleft attaches to ventricular septum. Ventricular septal defect has been surgically closed. The two segments of the anterior MV leaflet connect with a very hypoplastic posteromedial papillary muscle (PMPM). A much larger anterolateral papillary muscle (ALPM) is fused with leaflet tissue of MV. Interchordal spaces are obliterated. Left atrial appendage (LAA) was enlarged and hypertrophied. Left ventricular inlet/outlet ratio = Cleft functions as orifice of MV and is very stenotic. The resulting pulmonary venous hypertension caused pulmonary artery hypertension despite stenosis of RV outflow. (Ao = aorta; LAD = left anterior descending coronary artery; LPA = left pulmonary artery; RV = right ventricle; VS = ventricular septum.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

6. Fig 5
Left ventricle of explanted heart of 11-year-old boy with transposition {S, D, D} after Senning atrial switch in early infancy (case 9, Table 2). Mitral valve (MV) cleft attaches to free wall of left ventricle (LV) superiorly to transposed pulmonary valve, which has been replaced with a prosthetic pulmonary valve (PV). Free margins of mitral valve cleft are thickened and rolled, although the patient had minimal mitral regurgitation. Thickened free margins of cleft and fibrous ridge (impact lesion) on the septal surface of LV caused severe left ventricular outflow obstruction. Anterolateral papillary muscle (ALPM) and posteromedial papillary muscle (PMPM) are hypertrophied and close together. Left ventricular inlet/outlet ratio = 1.
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

7. Fig 6
Open left ventricle of 11-month-old girl with double-outlet right ventricle {S,D,D} and conoventricular ventricular septal defect (VSD) (case 4, Table 3). Mitral valve (MV) cleft is incomplete and its raphé attaches on anterosuperior crest of VSD. Posteromedial papillary muscle is twice the size of the anterolateral papillary muscle, corresponding to larger posterior part of the anterior mitral leaflet. Left ventricle is markedly hypertrophied. Conal septum (CS; not seen in this figure) is malpositioned to right of ventricular septum. Left ventricular inlet/outlet ratio = 1.
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

8. Fig 7
Left ventricular outflow of 6-year-old boy with transposition {S, D, D} and conoventricular ventricular septal defect (VSD) with posterior conal septal malalignment (case 7, Table 2). Mitral valve (MV) cleft attaches to free wall of LV above and to left of PV and, in combination with posteriorly malaligned conal septum, produces significant subpulmonary stenosis. The MV cleft is incomplete and narrow, dividing equally the anterior MV leaflet. Anterolateral papillary muscle (ALPM) and posteromedial papillary muscle (PMPM) are of equal size and close to each other. Left ventricular inlet/outlet ratio = 1. It is obvious that surgical closure of the MV cleft will not affect LV outflow obstruction. (PV = pulmonary valve.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

9. Fig 8
(A) Right ventricle of 17-year-old boy with double-outlet right ventricle {S, D, D} and conoventricular ventricular septal defect (VSD) with rightward malalignment of conal septum (case 5, Table 3). (B) Left ventricle (LV) of the same heart. Mitral valve (MV) attaches to left ventricular free wall to the left and slightly inferior to the PV. Free margins of complete, wide MV cleft are thin and not rolled, indicative of absence of mitral regurgitation. Both parts of MV cleft attach to a single posteromedial papillary muscle (PMPM). Left ventricular inlet/outlet ratio = 1. (Ao = aorta; Inf S = infundibular septum [conal septum]; PV = pulmonary valve; To Ao = stenotic outflow tract to aorta; TV = tricuspid valve.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)

10. Fig 9
Left ventricle (LV) of 3-day-old girl with transposition {S, L, L} and small restrictive ventricular septal defect (VSD) (case 2, Table 4). Complete, narrow mitral valve (MV) cleft attaches to LV free wall next to right upper border of transposed PV. Posteromedial papillary muscle (PMPM) group is much larger than anterolateral papillary muscle (ALPM), corresponding to larger size of posterior segment of cleft anterior leaflet of MV. Left ventricular inlet/outlet ratio = 1. (CS = conal septum; PV = pulmonary valve; Transposition {S,L,L} = TGA with solitus atria, L-loop ventricles, and L-TGA.)
The Annals of Thoracic Surgery  , DOI: ( /S (03)00167-X)