1
|
Sun D, Schaff HV, Nishimura RA, Geske JB, Dearani JA, Ommen SR. Transapical Ventricular Remodeling for Hypertrophic Cardiomyopathy With Systolic Cavity Obliteration. Ann Thorac Surg 2022; 114:1284-1289. [PMID: 35339438 DOI: 10.1016/j.athoracsur.2022.02.073] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/21/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Some patients with hypertrophic cardiomyopathy (HCM) present with reduced left ventricular (LV) stroke volume and elongated systolic cavity obliteration due to symmetric LV hypertrophy. In this report, we detail our experience with transapical septal myectomy to enlarge the LV volume and to relieve cavity obliteration in this unique subgroup of patients with HCM. METHODS We analyzed 38 patients with HCM who had extended symmetric LV hypertrophy and underwent transapical septal myectomy to enlarge the LV cavity from February 2001 to May 2021. RESULTS At the time of evaluation for operation, 84.2% (n = 32) of the patients were in New York Heart Association class III/IV. The peak oxygen consumption was 51.5% (44.0%-58.0%) of the normal predicted values on the preoperative exercise stress test (n = 16). Preoperative left atrial sizes in this cohort were enlarged (left atrial volume index, 39.0 [33.5-51.5] mL/m2), despite only 4 patients with moderate or greater mitral valve regurgitation. All patients underwent transapical septal myectomy to enlarge the LV cavity size. There was no postoperative (within 30 days) death. During a median (interquartile range) follow-up of 3.4 (0.7-6.9) years, the estimated survival rates were 100%, 92%, and 87% at 1, 3, and 5 years, respectively. Follow-up surveys suggested that 16 of the 17 contacted patients experienced improvement in their heart function after the procedure. CONCLUSIONS Transapical myectomy to enlarge LV cavity volume can be performed safely with good early survival and functional results. This procedure is an important alternative to cardiac transplantation for HCM patients with systolic cavity obliteration and progressive heart failure.
Collapse
Affiliation(s)
- Daokun Sun
- Department of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota
| | - Hartzell V Schaff
- Department of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota.
| | - Rick A Nishimura
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - Jeffrey B Geske
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - Joseph A Dearani
- Department of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota
| | - Steve R Ommen
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
2
|
Left ventricular ejection hemodynamics before and after relief of outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy and valvular aortic stenosis. J Thorac Cardiovasc Surg 2020; 159:844-852.e1. [DOI: 10.1016/j.jtcvs.2019.03.071] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 03/07/2019] [Accepted: 03/21/2019] [Indexed: 02/01/2023]
|
3
|
Elsayes AH, Joshi B, Wessler B, Rowin EJ, Maron MS, Cobey FC. A Case of Multiple Ventricular Gradients. J Cardiothorac Vasc Anesth 2018; 32:1829-1832. [PMID: 29459110 DOI: 10.1053/j.jvca.2018.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Ali H Elsayes
- Tufts Medical Center, Department of Anesthesiology and Perioperative Medicine, Boston, MA
| | - Brijen Joshi
- The Johns Hopkins University School of Medicine, Department of Anesthesiology and Critical Care Medicine, Baltimore, MD
| | - Benjamin Wessler
- Tufts Medical Center, Department of Medicine, Division of Cardiology, Boston, MA
| | - Ethan J Rowin
- Tufts Medical Center, Department of Medicine, Division of Cardiology, Boston, MA
| | - Martin S Maron
- Tufts Medical Center, Department of Medicine, Division of Cardiology, Boston, MA
| | - Frederick C Cobey
- Tufts Medical Center, Department of Anesthesiology and Perioperative Medicine, Boston, MA.
| |
Collapse
|
4
|
Pasipoularides A. Fluid dynamic aspects of ejection in hypertrophic cardiomyopathy. Hellenic J Cardiol 2011; 52:416-426. [PMID: 21940289 PMCID: PMC5788450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
|
5
|
Cheng TO. Mechanisms of variability of left ventricular outflow tract gradient in hypertrophic cardiomyopathy. Int J Cardiol 2010; 145:169-171. [DOI: 10.1016/j.ijcard.2010.05.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 05/26/2010] [Indexed: 10/19/2022]
|
6
|
Evaluation of Myocardial Disease in the Cardiac Catheterization Laboratory. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
7
|
Abstract
The basics of pulsatile ejection dynamics are reviewed in order to clarify the relationships among left ventricular and aortic pressures, intra-left ventricular and aortic flow velocities, and cardiovascular sound. The principles of turbulent flow are examined using the Reynolds number concept, and the evidence for cause-and-effect relationships between turbulent flow and murmur generation is presented. Examples of hemodynamics and phonocardiography are given for normal subjects and are compared to patients with aortic stenosis and hypertrophic cardiomyopathy. The concepts presented are used to analyze the results of a new study suggesting increased intraventricular velocities as a new cause for systolic murmurs in adults.
Collapse
|
8
|
|
9
|
Lin CS, Chen KS, Lin MC, Fu MC, Tang SM. The relationship between systolic anterior motion of the mitral valve and the left ventricular outflow tract Doppler in hypertrophic cardiomyopathy. Am Heart J 1991; 122:1671-82. [PMID: 1957762 DOI: 10.1016/0002-8703(91)90286-q] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In an attempt to investigate the role of left ventricular blood outflow in the generation of systolic anterior motion (SAM) of the mitral valve in patients with hypertrophic cardiomyopathy, we precisely analyzed the temporal relation of SAM and the left ventricular outflow tract (LVOT) systolic Doppler events obtained at the maximal mitral-septal apposition or equivalent area in eight patients with severe SAM, in five patients with mild/moderate SAM, and in seven patients with no SAM, using M-mode and pulsed Doppler echocardiography; the results were compared with those in 10 normal subjects. In all 13 patients with SAM, the timing of SAM generation corresponded to the LVOT Doppler events either between the onset of SAM and the onset of Doppler (r = 0.834, p less than 0.0001) or between the peak of SAM and the peak of Doppler (r = 0.836, p less than 0.0001). The excursion rate of the development of SAM showed a correlation with the LVOT blood outflow acceleration (r = 0.828, p less than 0.0001). The timing of SAM resolution also correlated with the Doppler events, either between the offset of SAM and the offset of Doppler (r = 0.795, p less than 0.001) or the end of SAM and the end of Doppler (r = 0.859, p less than 0.0001). The LVOT blood outflow deceleration showed a correlation with the regression rate of SAM (r = 0.668, p less than 0.013). The LVOT blood outflow acceleration was significantly higher in patients with severe SAM than in patients with mild/moderate SAM or no SAM. This study suggests that the high LVOT blood outflow acceleration in early systole possibly plays an important part in the generation of the Bernoulli pressure drop and results in anterior motion of the mitral valve. At mid-systole, a drag force and/or suction effect of pressure drop produced by continuous outflow blood may sustain the anterior motion of the mitral valve. At late systole, as the blood flow decelerates, the regression of SAM then occurs.
Collapse
Affiliation(s)
- C S Lin
- Department of Internal Medicine, Chung Shan Medical and Dental College Hospital, Taichung, Taiwan, Republic of China
| | | | | | | | | |
Collapse
|
10
|
Haddy S, Matthews RV. Transesophageal echocardiographic diagnosis of left ventricular cavity obliteration causing failure to separate from cardiopulmonary bypass. J Cardiothorac Vasc Anesth 1991; 5:490-3. [PMID: 1932653 DOI: 10.1016/1053-0770(91)90125-d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S Haddy
- Department of Anesthesiology, Hospital of the Good Samaritan, Los Angeles, CA 90017
| | | |
Collapse
|
11
|
Hoit BD, Penonen E, Dalton N, Sahn DJ. Doppler color flow mapping studies of jet formation and spatial orientation in obstructive hypertrophic cardiomyopathy. Am Heart J 1989; 117:1119-26. [PMID: 2711973 DOI: 10.1016/0002-8703(89)90871-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
To help clarify the mechanism of outflow tract obstruction and systolic anterior motion of the anterior leaflet of the mitral valve and their relation to the geometry of the left ventricle, we studied left ventricular outflow tract flow in 20 patients with hypertrophic cardiomyopathy (HCM) using two-dimensional Doppler flow mapping. We compared our results with outflow tract flow in 10 patients with isolated valvular aortic stenosis, (AS) and with those in 10 healthy volunteers. In HCM, a 94- to 145-degree angle (mean 111.4 +/- 11.9 degrees) developed between the direction of left ventricular outflow tract flow acceleration and aortic valve outflow, resulting in posterolaterally directed left ventricular outflow jets. The angle of the outflow jet and the peak velocity of the jet measured with continuous wave Doppler (as an indicator of the severity of obstruction) correlated well (r = -0.81, SEE = 7.8 degrees). Jet narrowing during ejection measured just proximal to the point of systolic anterior motion was 42 +/- 11% in HCM and was weakly correlated with peak jet velocity (r = 0.61, SEE = 8.9 degrees). Aliasing of left ventricular outflow occurred proximal to systolic anterior motion of the mitral valve, and color M-mode demonstrated temporal and spatial flow acceleration proximal to systolic anterior motion, providing evidence for obstruction at that site. In AS, left ventricular outflow tract jets were more parallel to the axis of aortic outflow (129 to 153 degree, 138.4 +/- 8.1 degrees). Jet narrowing was only 8 +/- 5% compared to HCM (both p less than 0.05), and flow acceleration occurred proximal to the stenotic valve.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- B D Hoit
- Division of Cardiology, Veterans Administration Medical Center, San Diego, Calif
| | | | | | | |
Collapse
|
12
|
Cannon RO, McIntosh CL, Schenke WH, Maron BJ, Bonow RO, Epstein SE. Effect of surgical reduction of left ventricular outflow obstruction on hemodynamics, coronary flow, and myocardial metabolism in hypertrophic cardiomyopathy. Circulation 1989; 79:766-75. [PMID: 2924410 DOI: 10.1161/01.cir.79.4.766] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To assess the impact of operative reduction of left ventricular outflow obstruction in hypertrophic cardiomyopathy, measurements of great cardiac vein flow, oxygen and lactate content, left ventricular pressures, and cardiac index were measured at rest and during pacing stress in 20 consecutive patients (13, myotomy-myectomy; six, mitral valve replacement; one, both myotomy-myectomy and mitral valve replacement) who underwent both preoperative and postoperative studies. All had angiographically normal epicardial coronary arteries. Operation resulted in reduction in outflow gradient (64 +/- 38 to 4 +/- 7 mm Hg, p less than 0.001) and in left ventricular systolic pressure (186 +/- 32 to 128 +/- 22 mm Hg, p less than 0.001) and was associated with reduction in great cardiac vein flow (101 +/- 26 to 78 +/- 16 ml/min, p less than 0.001) and oxygen consumption in the anterior left ventricle and septum (11.9 +/- 4.1 to 8.4 +/- 1.9 ml O2/min, p less than 0.001) in the basal state. During rapid atrial pacing, 13 of 20 patients experienced chest pain postoperatively, whereas all 20 developed chest pain during preoperative pacing, with an improvement in pacing anginal threshold (or heart rate 150 if no chest pain was experienced) of 16 +/- 18 beats/min (p less than 0.001). The peak great cardiac vein flow (161 +/- 41 to 131 +/- 45 ml/min, p less than 0.025) and myocardial oxygen consumption (19.4 +/- 6.1 to 14.3 +/- 5.5 ml O2/min, p less than 0.005) during pacing, which correlated directly with the severity of the basal left ventricular gradient (p = 0.011 and p = 0.002, respectively), were also reduced by surgery. Lactate metabolism during pacing changed from net production before surgery to net consumption after operation (-17 +/- 47.6 to 4.4 +/- 29.8 mumol/min, p less than 0.01), with six of 20 patients producing lactate after surgery compared with 13 of 20 before surgery (p = 0.06). The six patients with the highest peak great cardiac vein flow (greater than 175 ml/min) during preoperative pacing had greater symptom and metabolic benefit during pacing after surgery compared with the 14 patients with lower peak coronary flow. Postpacing left ventricular end-diastolic pressure (30 +/- 7 to 23 +/- 7 mm Hg, p less than 0.001) and pulmonary artery wedge pressure (24 +/- 6 to 20 +/- 5, p less than 0.001) were reduced after surgery.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- R O Cannon
- Cardiology Branche, National Heart, Lung, and Blood Institute, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|
13
|
Come PC, Riley MF, Carl LV, Lorell B. Doppler evidence that true left ventricular-to-aortic pressure gradients exist in hypertrophic cardiomyopathy. Am Heart J 1988; 116:1253-61. [PMID: 3189142 DOI: 10.1016/0002-8703(88)90448-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The etiology of systolic left ventricular-to-aortic pressure gradients in hypertrophic cardiomyopathy is still controversial. While cavity obliteration has been proposed by some investigators as the cause for recording of a high left ventricular systolic pressure, the concept of left ventricular outflow tract obstruction has received more experimental support. To investigate further whether left ventricular pressure truly exceeds aortic pressure and implies obstruction, we studied, with imaging and Doppler echocardiographic techniques, five patients with asymmetric septal hypertrophy and systolic anterior movement of the mitral valve occasionally causing it to abut upon the septum. All had outflow tract pressure gradients (peak 85 +/- 10 mm Hg) and trace to mild mitral regurgitation. Continuous wave Doppler study recorded peak flow velocities in the outflow tract (4.6 +/- 0.3 m/sec), and mitral regurgitant (mean 6.6 +/- 0.3 m/sec) jets. Aortic systolic and diastolic blood pressures were measured by cuff sphygmomanometry, and simultaneous carotid pulse tracings were recorded. The magnitude of systolic aortic pressure was determined at the time of peak velocity in the mitral regurgitant jet. Since the peak systolic pressure gradient across the mitral valve (left ventricular minus left atrial pressure) should equal 4 times the square of the peak velocity (V) in the mitral regurgitant jet, peak left ventricular systolic pressure should equal 4 x V2 plus the height of left atrial pressure at the time of peak mitral regurgitant velocity. In each case, calculations were made assuming an upper normal left atrial pressure of 10 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- P C Come
- Charles A. Dana Research Institute, Beth Israel Hospital, Boston, MA 02215
| | | | | | | |
Collapse
|
14
|
Angel J, Domingo E, Serrat R, Anivarro I, Soler-Soler J. Differences of postextrasystolic behavior of left ventricular and aortic pressures between fixed and dynamic left ventricular outflow tract stenosis. Chest 1988; 94:1058-62. [PMID: 2460295 DOI: 10.1378/chest.94.5.1058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The dynamic behavior of fixed LV outflow tract stenosis partly resembles that of OCM. To analyze their differences we studied basal and postextrasystolic (post-PVC) peak-to-peak LV aortic gradients, aortic systolic pressure, and pulse pressure in 14 OCM and in 36 pure VAS without two-dimensional echocardiographic findings of OCM. Fifteen mild VAS had basal gradients similar to those of OCM (39 +/- 17 mm Hg vs 24 +/- 16 mm Hg). Patients with OCM show a post-PVC gradient (109 +/- 41 mm Hg) similar to that of VAS (110 +/- 50 mm Hg). However, the latter were departing from much higher gradients (VAS 72 +/- 30 mm Hg vs OCM 24 +/- 16 mm Hg). Decrement of post-PVC aortic systolic pressure and pulse pressure were frequent in both groups, but decrement of pulse pressure greater than 5 mm Hg were more frequent in OCM. We concluded that (1) post-PVC increased aortic gradients and decreased aortic systolic pressure occurred in both VAS and OCM; (2) post-PVC decreased aortic pulse pressure might occur in VAS; and (3) association of post-PVC gradient increment greater than 75 percent and pulse pressure decrement greater than 5 mm Hg are strongly suggestive of OCM.
Collapse
Affiliation(s)
- J Angel
- Servei de Cardiologia Hospital General Vall d'Hebron, Barcelona, Spain
| | | | | | | | | |
Collapse
|
15
|
Stewart WJ, Schiavone WA, Salcedo EE, Lever HM, Cosgrove DM, Gill CC. Intraoperative Doppler echocardiography in hypertrophic cardiomyopathy: correlations with the obstructive gradient. J Am Coll Cardiol 1987; 10:327-35. [PMID: 3598004 DOI: 10.1016/s0735-1097(87)80015-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Although significant pressure gradients can be recorded across the left ventricular outflow tract in patients with hypertrophic cardiomyopathy, controversy exists regarding the presence or absence of true obstruction. Ten patients with hypertrophic cardiomyopathy were studied at the time of septal myectomy. A sterile continuous wave Doppler transducer was placed on the ascending aorta and directed toward the left ventricular outflow tract to measure velocity simultaneously with invasive gradient measured using solid-state hub transducers by direct puncture of the left ventricle and aorta. Simultaneous Doppler velocity and invasive gradient measurements (n = 33) were made at rest, before and after myectomy and during interventions with isoproterenol, volume loading and phenylephrine. High velocity flow with a characteristic contour was recorded in patients with a significant gradient. Using the modified Bernoulli equation (gradient = 4 X velocity), a good correlation was found between the Doppler-derived gradient and the peak instantaneous gradient measured invasively (r = 0.93, y = 0.89X + 12, p = 0.0001). Changes in gradient and velocity due to interventions also correlated well (r = 0.96, y = 0.91X - 3, p = 0.0001). Continuous wave Doppler echocardiography can accurately estimate the outflow tract gradient. The magnitude, timing and contour of these high velocity flow signals support the hypothesis that true obstruction is present in patients with hypertrophic cardiomyopathy who have a significant gradient.
Collapse
|
16
|
Maron BJ, Bonow RO, Cannon RO, Leon MB, Epstein SE. Hypertrophic cardiomyopathy. Interrelations of clinical manifestations, pathophysiology, and therapy (1). N Engl J Med 1987; 316:780-9. [PMID: 3547130 DOI: 10.1056/nejm198703263161305] [Citation(s) in RCA: 613] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
17
|
Cogswell TL, Sagar KB, Wann LS. Left ventricular ejection dynamics in hypertrophic cardiomyopathy and aortic stenosis: comparison with the use of Doppler echocardiography. Am Heart J 1987; 113:110-6. [PMID: 3799425 DOI: 10.1016/0002-8703(87)90017-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Left ventricular ejection dynamics of 15 patients with hypertrophic cardiomyopathy (nine obstructive, six nonobstructive) were compared to those in 12 age-matched normal subjects and 10 patients with valvular aortic stenosis by means of combined two-dimensional and Doppler echocardiography. Doppler peak flow velocities in obstructive (HOCM, 2.5 +/- 1.3 m/sec) and nonobstructive (HNCM, 2.6 +/- 0.6 m/sec) hypertrophic cardiomyopathy, as well as in patients with aortic stenosis (AS, 3.6 +/- 1.3 m/sec) were significantly higher than in the normal population (1.0 +/- 0.2 m/sec; p less than 0.001 for all comparisons), but did not differ from each other. The HOCM patients had time to peak velocity (154 +/- 55.7 msec) that was higher than that in both HNCM (86 +/- 8.4 msec) and normal groups (84.5 +/- 8.9 msec; p less than 0.001 for both comparisons), but did not differ from those in AS (117 +/- 52.5 msec). The total ejection time did not differ between HOCM (348.2 +/- 91.1 msec) and AS (328.8 +/- 30.4 msec) groups, but was prolonged in HOCM compared to HNCM (198 +/- 21.0 msec) and normal groups (233 +/- 28.3 msec; p less than 0.001 for both comparisons). The normal and HNCM groups did not differ in time to peak or total ejection time measurements. The percent of flow velocity present in the initial third of the systolic velocity integral for HOCM (44.5% +/- 5.9) and HNCM (49.4% +/- 2.5) groups was greater than for normals (36.2% +/- 5.4; p less than 0.05 for both comparisons), but HOCM values did not differ from HNCM values.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
18
|
Maron BJ, Epstein SE. Clinical significance and therapeutic implications of the left ventricular outflow tract pressure gradient in hypertrophic cardiomyopathy. Am J Cardiol 1986; 58:1093-6. [PMID: 3776861 DOI: 10.1016/0002-9149(86)90118-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
19
|
Yock PG, Hatle L, Popp RL. Patterns and timing of Doppler-detected intracavitary and aortic flow in hypertrophic cardiomyopathy. J Am Coll Cardiol 1986; 8:1047-58. [PMID: 2876020 DOI: 10.1016/s0735-1097(86)80381-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study describes the velocity characteristics of left ventricular and aortic outflow in 25 patients with hypertrophic "obstructive" cardiomyopathy. Systematic pulsed and continuous wave Doppler analysis combined with phonocardiography and M-mode echocardiography was used to establish the pattern and timing of outflow in the basal and provoked states. This analysis suggests that 1) the high velocity left ventricular outflow jet can be reliably discriminated from both aortic flow and the jet of mitral regurgitation using Doppler ultrasound; 2) the Doppler velocity contour responds in a characteristic fashion to provocative influences including extrasystole and Valsalva maneuver; 3) the onset of mitral regurgitation occurs well before detectable systolic anterior motion of the mitral valve; 4) left ventricular flow velocities are elevated at the onset of systolic anterior motion of the mitral valve, suggesting a significant contribution of the Venturi effect in displacing the leaflets and chordae; 5) the high velocities of the outflow jets are largely dissipated by the time flow reaches the aortic valve; and 6) late systolic flow in the ascending aorta is nonuniform, with formation of distinct eddies that may contribute to "preclosure" of the aortic valve.
Collapse
|
20
|
Criley JM, Siegel RJ. Obstruction is unimportant in the pathophysiology of hypertrophic cardiomyopathy. Postgrad Med J 1986; 62:515-29. [PMID: 3534838 PMCID: PMC2418802 DOI: 10.1136/pgmj.62.728.515] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
There has been a longstanding controversy about the significance of intracavitary pressure gradients in hypertrophic cardiomyopathy (HCM). It has been generally assumed that the gradient is the result of an 'obstruction' that impedes left ventricular outflow and which can be relieved by operative intervention. In the first decade after the discovery of HCM (1957-66), the site of 'obstruction' was thought to be a muscular sphincter or contraction ring in the submitral region of the left ventricle, and operations designed to emulate pyloromyectomy (for hypertrophic pyloric stenosis) were developed. Following a challenge to the existence of the 'contraction ring' and an alternative non-obstructive explanation of the pressure gradient, the site of 'obstruction' was translocated to a point of apposition between the anterior mitral leaflet and the interventricular septum, a result of systolic anterior motion (SAM) of the mitral valve. Despite the translocation of the site and mechanism of 'obstruction', the operation for 'relief of obstruction' has not changed significantly. The newer site of 'obstruction' has been challenged on the grounds that the ventricle is not demonstrably impeded in its emptying; when a gradient is provoked, the ventricle empties more rapidly and more completely than it does without a gradient. In addition to a non-obstructive explanation of the gradient, other phenomena thought to be indicative of 'obstruction' can be explained by rapid and complete emptying of the ventricle (cavitary obliteration). Since the morbidity and mortality of symptomatic HCM patients without pressure gradients may exceed that of patients with pressure gradients, it is suggested that 'obstruction' may be unimportant in the pathophysiology of HCM and attention should be focused on abnormal diastolic function and life threatening arrhythmias.
Collapse
|
21
|
Tencate FJ, Mayala AP, Vletter WB, Roelandt J. Color-coded Doppler imaging of systolic flow patterns in hypertrophic cardiomyopathy. INTERNATIONAL JOURNAL OF CARDIAC IMAGING 1985; 1:217-23. [PMID: 3843410 DOI: 10.1007/bf01568669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We studied 11 patients with hypertrophic cardiomyopathy by color Doppler echocardiography (Group I: 6 patients with outflow obstruction, and Group II: 5 patients without outflow obstruction) to assess systolic structure and function as observed by cross-sectional echocardiography in relation to the flow dynamics. The structure and function included systolic anterior motion of mitral valve (SAM), midsystolic aortic valve closure (AoC), systolic cavity obliteration and the presence and timing of mitral incompetence. Their occurrence and timing was related to presence of aortic systolic flow and presence of turbulence. While all patients in Group I had SAM and turbulence, none of the patients in Group II had SAM nor turbulence. Early mitral incompetence appearing before SAM and turbulence, occurred in all patients of Group I and in none of Group II. Midsystolic aortic valve closure was only present in Group I and blood flow was unilaterally directed so that only 60% of aortic cross-sectional area showed blood flow. We conclude that mitral incompetence in hypertrophic cardiomyopathy in early systole is common when outflow gradient is present and is independent of mitral incompetence of mid- and late systole. During SAM, turbulence in the subaortic area and mid and late mitral incompetence occurred simultaneously. The midsystolic aortic valve closure was related to the unilaterally directed blood flow through the aortic cross-sectional area.
Collapse
|
22
|
Abstract
HCM is a disorder associated with significant morbidity and mortality and a propensity to cause sudden, often unexpected death. The similarity to the symptom complex of aortic stenosis and the presence of a pressure gradient justified the initial assumption that obstruction was of prime importance in HCM and that relief of obstruction was the focal point of rational therapy. However, it is our belief that the dogma of obstruction has impeded progress in and obscured the understanding of HCM and interpretation of its manifestations. The purpose of this article is to call attention to significant discrepancies in the obstructive concept that have been reinforced as new techniques emerged that have allowed further study of the disease. Since neither the presence of a gradient nor SAM can be justifiably equated with the presence of an obstruction, it is proposed that the appellation "obstruction" be reserved for those cases in which the rate of outflow or the rate or degree of ventricular emptying are demonstrably impeded, as in aortic stenosis. Therapy with beta-adrenergic-receptor and calcium channel-blocking agents have shown promise for alleviating symptoms and possibly prolonging life without systematically or predictably affecting the pressure gradient, probably because of their beneficial effects on ventricular relaxation and diastolic filling. Antiarrhythmic therapy has been effective in reducing mortality. Ideally, prevention or regression of the pathologic hypertrophy should be the major focus of future therapeutic interventions in hypertrophic cardiomyopathy.
Collapse
|