Echocardiographic Features of Subpulmonic Obstruction in Dextro-transposition of the Great Vessels By NAVIN C. NANDA, M.D., RAYMOND GRAMIAK, M.D., JAMES A. MANNING, M.D., AND
ELLIOT 0. LIPCHIK, M.D.
SUMMARY
Eleven patients with dextro-transposition of the great vessels (TGV) and subpulmonic (left ventricular outflow) obstruction documented by cardiac catheterization and angiography were studied by echocardiography. Echocardiographic features which characterized the outflow obstruction included a) prolonged diastolic apposition of the mitral valve with the ventricular septum (10 patients), b) smaller width of the pulmonary artery as compared to the aortic root (10 cases), and c) narrowing of the subpulmonic area demonstrated by beam angulation studies through the planes of the mitral valve and the pulmonary artery (five cases). In addition, four patients showed abnormal systolic anterior movements (SAMs) of the anterior mitral leaflet resembling those observed in idiopathic hypertrophic subaortic stenosis. The SAMs were large in three patients and may have accentuated the outflow obstruction. Additional evidence for this was provided by the movement of the pulmonary valve towards closure with the onset of the mitral SAMs. These features were uncommon or absent in a comparison group of 17 patients with TGV and no outflow obstruction. Echocardiography appears to be useful in the diagnosis of subpulmonic muscular obstruction in TGV. Demonstration of definite mitral SAMs in some patients suggests the presence of associated functional obstruction of the type seen in idiopathic hypertrophic subaortic stenosis.
Additional Indexing Words: Mitral-sseptal diastolic apposition Ultrasound Left ventricular outflow tract obstruction Mitral-septal continuity SAM ASH
from this laboratory described an echocardiographic technique for the detection of the pulmonary valve and obtained anatomic validation of cusp echoes using indocyanine green injection during cardiac catheterization.8 Development of the capability of studying both semilunar valves by ultrasound has resulted in its application in the identification of patients with dextro-transposition of the great vessels.9 The purpose of this report is to describe echocardiographic features which characterize left ventricular outflow obstruction in patients with dextrotransposition of the great vessels.
THE TECHNIQUE of atrial septectomy using the Blalock-Hanlon procedure' as well as the more recent introduction of Rashkind's balloon septostomy2 have provided effective palliation in patients with transposition of the great vessels. These procedures permit survival of an infant suffering from this malformation until total physiologic correction using an intra-atrial baffle (Mustard's operation)3 is feasible. Coexistence of subpulmonic obstruction complicates the surgical repair and often requires a radically different type of operation.4 Thus its recognition is of crucial value. Ultrasound represents a noninvasive, nontraumatic, repeatable diagnostic technique, the role of which is well established in the evaluation of various cardiovascular conditions.5' 6 7 The aortic root has been well studied by ultrasound.5 A recent study
Materials and Methods Eleven patients with dextro-transposition of the great vessels and left ventricular outflow obstruction who were examined by echocardiography formed the basis of the study. There were seven males and four females. Their ages ranged from one month to 15 years, the average being five years. The diagnosis of subpulmonary obstruction was made by angiography. Left ventricular outflow narrowing and/or bulging of the ventricular septum into the subpulmonic portion of the left ventricular outflow area was present in all patients. Associated lesions included pulmonary valvular stenosis in two patients, ventricular septal defect in four and patent ductus arteriosus in one patient. The pulmonary
From the Departments of Medicine (Cardiology Unit), Radiology, and Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York. Address for reprints: Navin C. Nanda, M.D., Cardiology Unit, University of Rochester Medical School, Rochester, New York 14642. Received October 7, 1974; revision accepted for publication November 13, 1974. Circulation, Volume 51, March 1975
515
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
5-16
NANDA ET AL.
artery
was not entered in three patients. The left ventricular systolic pressure measurements in these were equal to or higher than the right ventricular pressure values. In the remaining eight patients the systolic pressure gradient across the pulmonary valve was 36 mm Hg or more. A comparison group of 17 patients (average age four years) with dextro-transposition of the great vessels without evidence of subpulmonic or pulmonic obstruction as evidenced by cardiac catheterization and/or angiography was also studied. All echocardiographic examinations were performed using a commercially available echograph (Picker) and a 2 MHz collimated transducer. Continuous records were made on 35 mm film by means of a Fairchild Oscilloscope Record camera and a dual beam oscilloscope operating as a slave. Routine echocardiographic examinations of the mitral and tricuspid valves were performed. Echoes from the anteriorly placed aortic root were obtained by medial transducer angulation while those from the posteriorly placed pulmonary root were detected by relatively lateral beam angulation.9 The ultrasonic beam was gradually moved from the mitral valve to the pulmonary root in an attempt to evaluate continuity between the two structures as well as to delineate any area of subpulmonic narrowing. The presence of prolonged apposition between the mitral valve and the left side of the ventricular septum in diastole indicative of the narrow left ventricular outflow tract was noted.'` The mitral valve was also studied for evidence of abnormal systolic anterior movement (SAM).` An attempt was made to obtain echoes from the ventricular septum and the posterior wall of the left ventricle utilizing a method previously described.'2 The outer diameters of both the pulmonary and aortic roots were measured at the onset of diastole. Results
reached up to the ventricular septum in three cases while they were small in the remaining patient. The anterior leaflet of the mitral valve in one patient showed a coarse, irregular movement as it protruded into the left ventricular outflow tract in systole (fig. 3). No abnormalities of the mitral systolic segment were observed in this patient during the first echocardiographic study performed at the age of 31/2 weeks (when a satisfactory balloon septostomy was performed) and during a subsequent examination seven months later. At the time of the latter study, the left ventricular pressure obtained at cardiac catheterization was at the upper limits of normal at 35/2-7 mm Hg. The pulmonary artery was not entered. Definite SAMs were noted when the patient was re-examined at the age of two years. The left ventricular pressure at this time was higher, attaining a peak value of 60/4 mm Hg while the pulmonary artery pressure was 24/8 mm Hg. The pulmonary valve in all patients with large SAMs demonstrated a movement towards closure in the early part of systole coinciding with the onset of obstruction produced by the SAMs (figs. 1 and 2). Coarse systolic flutter was also observed. Asymmetric hypertrophy of the ventricular septum as evidenced by a ventricular septal to left ventricular posterior wall thickness ratio of greater than 1.3 was noted in two patients with large SAMs in whom adequate echoes could be obtained. In both patients the
The results of the present study are summarized in table 1. The two most impressive echocardiographic features which differentiated patients with dextrotransposition of the great vessels and left ventricular outflow obstruction from those without any evidence of subpulmonic narrowing were the presence of significant apposition of the mitral valve with the ventricular septum in diastole and a small sized pulmonary root as compared to the aorta (fig. 1). In the control group, prolonged mitral-septal diastolic apposition was rare, being present in only one patient. The pulmonary root was the larger vessel in most of the patients in the control category. The ratio of the width of the pulmonary artery to that of the aortic root ranged from 0.63 to 0.94 (average 0.72) in the obstruction group while it was 1.0 or greater in 14 of 17 patients in the control population (range 0.85 to 1.45, mean 1.11). Some of the patients in the obstruction group also presented with other echocardiographic features which indicated the nature of outflow narrowing. Definite, sharp systolic anterior movements of the mitral valve (SAMs), similar to those characteristically observed in patients with idiopathic hypertrophic subaortic stenosis," were observed in four patients (fig. 2). These movements were large, constantly seen and
Table 1 Echocardiographic Features Echo finding 1.
Diastolic mitral-septal appositioi
2.
PA < AO
3. Localized subpulmonie
TGV witlh LVOTO (11 patients)
10 (11)*
without LVOTO (1 7 patients'
TGV
90%C
1 (17) 6%
10 (10)
3 (17)
100%
18(X
(9)
(12)
narrowing
4. 5.
6.
SAMs
ASH
Systolic closure of PV
4 (11)
(17)
36%,
0
2 (7) 28C 4 (11) 36%C
0
(8) 0
0
(17) 0)
*The numbers in parentheses indicate the isumber of patients with echocardiographic studies adeqtuate for evaluation. Abbreviations: TGV = dextro-transposition of the great vessels; LVOTO = left ventricular outflow tract obstruction.; PA - width of the pulmonary artery; AO = width of the aorta; SAM = abnormal systolic anterior movement of the mitral valve; ASH = asymmetric ventricuilar septal hypertrophy; PV = pulmonary valve. Circulation, Volume 51, March 1975
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
ULTRASOUND IN LVOT OBSTRUCTION, TGA
57
1:-__S~~~~~~~o M*lt
-^
-1
Great vessel size ini dextro-transposition of the great represents 1 cm.) The width of the pulinonary root
nliogra
tn
;
ECC
=
Figure 1 vessels arid snbputlrnonic obstriction. (Scalc (P.A) is slightly smaller thani
the aorta
on
to;)
(A\O. PIIO
left of figulre = phonocar-
electrocardiogram 1.
width of the ventricular septum appeared to vary with changes in the ultrasonic beam position (fig. 3). In one the septal width increased when the beam was moved laterally in the direction of the cardiac apex while in ..
R~,- % 1
--
a
"-j
-0-
r"
the other the septal mass was thicker near its attachment to the pulmonary root. Echocardiographic studies of the subpulmonic area, performed by directing the beam from the pulmonary
"
JO&4w
-
m
M,
a
.
'A
Av
-~
t{ ..'_ ,~~~~~~~~~~~~~~~~~~ Yr0-^Opl 1, ~ pnw
-r-a ~~~
PHO~ ~ ~ ~c
4
ECG Figui Fuinitional sublp)ulnoienic obstrtuction iii dextro-trats position of the great vessels. (Scale otr top) left of figuire represetifs I cm.) The mitral ualve (MV) shows large abrnormal systolic aniterior movement (SAM) while the pulmonarycalve deniotistrates early systolic closuire wit/i the onset of obstrtuction produced by the niitral S.XAM. PA = pulotmtoary artery; 11IO= phonoc(ardiograni; ECG - elect rocardiograni. a
Circulation, Volume 51, March 1975
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
NANDA ET AL.
518
I~~~~~~~~~~~~~~~~~~ . 'r Vs
qMV
rri,*5Pw
ELLIOT 0. LIPCHIK, M.D.
SUMMARY
Eleven patients with dextro-transposition of the great vessels (TGV) and subpulmonic (left ventricular outflow) obstruction documented by cardiac catheterization and angiography were studied by echocardiography. Echocardiographic features which characterized the outflow obstruction included a) prolonged diastolic apposition of the mitral valve with the ventricular septum (10 patients), b) smaller width of the pulmonary artery as compared to the aortic root (10 cases), and c) narrowing of the subpulmonic area demonstrated by beam angulation studies through the planes of the mitral valve and the pulmonary artery (five cases). In addition, four patients showed abnormal systolic anterior movements (SAMs) of the anterior mitral leaflet resembling those observed in idiopathic hypertrophic subaortic stenosis. The SAMs were large in three patients and may have accentuated the outflow obstruction. Additional evidence for this was provided by the movement of the pulmonary valve towards closure with the onset of the mitral SAMs. These features were uncommon or absent in a comparison group of 17 patients with TGV and no outflow obstruction. Echocardiography appears to be useful in the diagnosis of subpulmonic muscular obstruction in TGV. Demonstration of definite mitral SAMs in some patients suggests the presence of associated functional obstruction of the type seen in idiopathic hypertrophic subaortic stenosis.
Additional Indexing Words: Mitral-sseptal diastolic apposition Ultrasound Left ventricular outflow tract obstruction Mitral-septal continuity SAM ASH
from this laboratory described an echocardiographic technique for the detection of the pulmonary valve and obtained anatomic validation of cusp echoes using indocyanine green injection during cardiac catheterization.8 Development of the capability of studying both semilunar valves by ultrasound has resulted in its application in the identification of patients with dextro-transposition of the great vessels.9 The purpose of this report is to describe echocardiographic features which characterize left ventricular outflow obstruction in patients with dextrotransposition of the great vessels.
THE TECHNIQUE of atrial septectomy using the Blalock-Hanlon procedure' as well as the more recent introduction of Rashkind's balloon septostomy2 have provided effective palliation in patients with transposition of the great vessels. These procedures permit survival of an infant suffering from this malformation until total physiologic correction using an intra-atrial baffle (Mustard's operation)3 is feasible. Coexistence of subpulmonic obstruction complicates the surgical repair and often requires a radically different type of operation.4 Thus its recognition is of crucial value. Ultrasound represents a noninvasive, nontraumatic, repeatable diagnostic technique, the role of which is well established in the evaluation of various cardiovascular conditions.5' 6 7 The aortic root has been well studied by ultrasound.5 A recent study
Materials and Methods Eleven patients with dextro-transposition of the great vessels and left ventricular outflow obstruction who were examined by echocardiography formed the basis of the study. There were seven males and four females. Their ages ranged from one month to 15 years, the average being five years. The diagnosis of subpulmonary obstruction was made by angiography. Left ventricular outflow narrowing and/or bulging of the ventricular septum into the subpulmonic portion of the left ventricular outflow area was present in all patients. Associated lesions included pulmonary valvular stenosis in two patients, ventricular septal defect in four and patent ductus arteriosus in one patient. The pulmonary
From the Departments of Medicine (Cardiology Unit), Radiology, and Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York. Address for reprints: Navin C. Nanda, M.D., Cardiology Unit, University of Rochester Medical School, Rochester, New York 14642. Received October 7, 1974; revision accepted for publication November 13, 1974. Circulation, Volume 51, March 1975
515
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
5-16
NANDA ET AL.
artery
was not entered in three patients. The left ventricular systolic pressure measurements in these were equal to or higher than the right ventricular pressure values. In the remaining eight patients the systolic pressure gradient across the pulmonary valve was 36 mm Hg or more. A comparison group of 17 patients (average age four years) with dextro-transposition of the great vessels without evidence of subpulmonic or pulmonic obstruction as evidenced by cardiac catheterization and/or angiography was also studied. All echocardiographic examinations were performed using a commercially available echograph (Picker) and a 2 MHz collimated transducer. Continuous records were made on 35 mm film by means of a Fairchild Oscilloscope Record camera and a dual beam oscilloscope operating as a slave. Routine echocardiographic examinations of the mitral and tricuspid valves were performed. Echoes from the anteriorly placed aortic root were obtained by medial transducer angulation while those from the posteriorly placed pulmonary root were detected by relatively lateral beam angulation.9 The ultrasonic beam was gradually moved from the mitral valve to the pulmonary root in an attempt to evaluate continuity between the two structures as well as to delineate any area of subpulmonic narrowing. The presence of prolonged apposition between the mitral valve and the left side of the ventricular septum in diastole indicative of the narrow left ventricular outflow tract was noted.'` The mitral valve was also studied for evidence of abnormal systolic anterior movement (SAM).` An attempt was made to obtain echoes from the ventricular septum and the posterior wall of the left ventricle utilizing a method previously described.'2 The outer diameters of both the pulmonary and aortic roots were measured at the onset of diastole. Results
reached up to the ventricular septum in three cases while they were small in the remaining patient. The anterior leaflet of the mitral valve in one patient showed a coarse, irregular movement as it protruded into the left ventricular outflow tract in systole (fig. 3). No abnormalities of the mitral systolic segment were observed in this patient during the first echocardiographic study performed at the age of 31/2 weeks (when a satisfactory balloon septostomy was performed) and during a subsequent examination seven months later. At the time of the latter study, the left ventricular pressure obtained at cardiac catheterization was at the upper limits of normal at 35/2-7 mm Hg. The pulmonary artery was not entered. Definite SAMs were noted when the patient was re-examined at the age of two years. The left ventricular pressure at this time was higher, attaining a peak value of 60/4 mm Hg while the pulmonary artery pressure was 24/8 mm Hg. The pulmonary valve in all patients with large SAMs demonstrated a movement towards closure in the early part of systole coinciding with the onset of obstruction produced by the SAMs (figs. 1 and 2). Coarse systolic flutter was also observed. Asymmetric hypertrophy of the ventricular septum as evidenced by a ventricular septal to left ventricular posterior wall thickness ratio of greater than 1.3 was noted in two patients with large SAMs in whom adequate echoes could be obtained. In both patients the
The results of the present study are summarized in table 1. The two most impressive echocardiographic features which differentiated patients with dextrotransposition of the great vessels and left ventricular outflow obstruction from those without any evidence of subpulmonic narrowing were the presence of significant apposition of the mitral valve with the ventricular septum in diastole and a small sized pulmonary root as compared to the aorta (fig. 1). In the control group, prolonged mitral-septal diastolic apposition was rare, being present in only one patient. The pulmonary root was the larger vessel in most of the patients in the control category. The ratio of the width of the pulmonary artery to that of the aortic root ranged from 0.63 to 0.94 (average 0.72) in the obstruction group while it was 1.0 or greater in 14 of 17 patients in the control population (range 0.85 to 1.45, mean 1.11). Some of the patients in the obstruction group also presented with other echocardiographic features which indicated the nature of outflow narrowing. Definite, sharp systolic anterior movements of the mitral valve (SAMs), similar to those characteristically observed in patients with idiopathic hypertrophic subaortic stenosis," were observed in four patients (fig. 2). These movements were large, constantly seen and
Table 1 Echocardiographic Features Echo finding 1.
Diastolic mitral-septal appositioi
2.
PA < AO
3. Localized subpulmonie
TGV witlh LVOTO (11 patients)
10 (11)*
without LVOTO (1 7 patients'
TGV
90%C
1 (17) 6%
10 (10)
3 (17)
100%
18(X
(9)
(12)
narrowing
4. 5.
6.
SAMs
ASH
Systolic closure of PV
4 (11)
(17)
36%,
0
2 (7) 28C 4 (11) 36%C
0
(8) 0
0
(17) 0)
*The numbers in parentheses indicate the isumber of patients with echocardiographic studies adeqtuate for evaluation. Abbreviations: TGV = dextro-transposition of the great vessels; LVOTO = left ventricular outflow tract obstruction.; PA - width of the pulmonary artery; AO = width of the aorta; SAM = abnormal systolic anterior movement of the mitral valve; ASH = asymmetric ventricuilar septal hypertrophy; PV = pulmonary valve. Circulation, Volume 51, March 1975
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
ULTRASOUND IN LVOT OBSTRUCTION, TGA
57
1:-__S~~~~~~~o M*lt
-^
-1
Great vessel size ini dextro-transposition of the great represents 1 cm.) The width of the pulinonary root
nliogra
tn
;
ECC
=
Figure 1 vessels arid snbputlrnonic obstriction. (Scalc (P.A) is slightly smaller thani
the aorta
on
to;)
(A\O. PIIO
left of figulre = phonocar-
electrocardiogram 1.
width of the ventricular septum appeared to vary with changes in the ultrasonic beam position (fig. 3). In one the septal width increased when the beam was moved laterally in the direction of the cardiac apex while in ..
R~,- % 1
--
a
"-j
-0-
r"
the other the septal mass was thicker near its attachment to the pulmonary root. Echocardiographic studies of the subpulmonic area, performed by directing the beam from the pulmonary
"
JO&4w
-
m
M,
a
.
'A
Av
-~
t{ ..'_ ,~~~~~~~~~~~~~~~~~~ Yr0-^Opl 1, ~ pnw
-r-a ~~~
PHO~ ~ ~ ~c
4
ECG Figui Fuinitional sublp)ulnoienic obstrtuction iii dextro-trats position of the great vessels. (Scale otr top) left of figuire represetifs I cm.) The mitral ualve (MV) shows large abrnormal systolic aniterior movement (SAM) while the pulmonarycalve deniotistrates early systolic closuire wit/i the onset of obstrtuction produced by the niitral S.XAM. PA = pulotmtoary artery; 11IO= phonoc(ardiograni; ECG - elect rocardiograni. a
Circulation, Volume 51, March 1975
Downloaded from http://circ.ahajournals.org/ at UNIV OF NORTH DAKOTA on June 13, 2015
NANDA ET AL.
518
I~~~~~~~~~~~~~~~~~~ . 'r Vs
qMV
rri,*5Pw
