The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Gary S. Mintz - One of the best experts on this subject based on the ideXlab platform.
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Dynamic changes in left ventricular outflow tract flow velocities after Amyl Nitrite inhalation in hypertrophic cardiomyopathy
American Heart Journal, 1991Co-Authors: Stavros Hadjimiltiades, Ioannis P. Panidis, Michael Mcallister, John Ross, Gary S. MintzAbstract:Abstract Doppler echocardiography was performed in 21 patients with hypertrophic cardiomyopathy (HC), in nine patients with no evidence of left ventricular (LV) hypertrophy by two-dimensional echocardiography, and in five patients with systemic hypertension and concentric LV hypertrophy. The LV outflow tract (LVOT) peak velocity was recorded by continuous wave Doppler technique at rest and after Amyl Nitrite inhalation. The LVOT pressure gradient was calculated by the modified Bernoulli equation. A significant increase in heart rate and a drop in systolic blood pressure were observed in all patients after Amyl Nitrite inhalation; no adverse effects were encountered. The peak LVOT velocity and pressure gradient increased significantly after provocation in all patients, but the increase was much more pronounced in patients with HC (peak LVOT velocity increased from 2.2 ± 0.8 to 4.3 ± 1.0 m/sec and peak gradient increased from 22 ± 17 to 78 ± 36 mm Hg). The Doppler spectral signal in patients with HC demonstrated a characteristic contour, with peak velocity occurring in late systole. However, the observed increase in LVOT peak velocity was not statistically different between treated (with β-blockers and calcium blockers) and untreated patients with HC. We conclude that LVOT peak velocity and pressure gradients in patients with HC can be readily assessed by Doppler echocardiography both at rest and after Amyl Nitrite inhalation. The dynamic changes in LVOT velocity induced by this provocation have certain characteristic features in obstructive HC but appear to be independent of the medical regimen used, at least in the dosages tested in our study.
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Dynamic changes in left ventricular outflow tract flow velocities after Amyl Nitrite inhalation in hypertrophic cardiomyopathy.
American heart journal, 1991Co-Authors: Stavros Hadjimiltiades, Ioannis P. Panidis, Michael Mcallister, John Ross, Gary S. MintzAbstract:Doppler echocardiography was performed in 21 patients with hypertrophic cardiomyopathy (HC), in nine patients with no evidence of left ventricular (LV) hypertrophy by two-dimensional echocardiography, and in five patients with systemic hypertension and concentric LV hypertrophy. The LV outflow tract (LVOT) peak velocity was recorded by continuous wave Doppler technique at rest and after Amyl Nitrite inhalation. The LVOT pressure gradient was calculated by the modified Bernoulli equation. A significant increase in heart rate and a drop in systolic blood pressure were observed in all patients after Amyl Nitrite inhalation; no adverse effects were encountered. The peak LVOT velocity and pressure gradient increased significantly after provocation in all patients, but the increase was much more pronounced in patients with HC (peak LVOT velocity increased from 2.2 +/- 0.8 to 4.3 +/- 1.0 m/sec and peak gradient increased from 22 +/- 17 to 78 +/- 36 mm Hg). The Doppler spectral signal in patients with HC demonstrated a characteristic contour, with peak velocity occurring in late systole. However, the observed increase in LVOT peak velocity was not statistically different between treated (with beta-blockers and calcium blockers) and untreated patients with HC. We conclude that LVOT peak velocity and pressure gradients in patients with HC can be readily assessed by Doppler echocardiography both at rest and after Amyl Nitrite inhalation. The dynamic changes in LVOT velocity induced by this provocation have certain characteristic features in obstructive HC but appear to be independent of the medical regimen used, at least in the dosages tested in our study.
Harry M. Lever - One of the best experts on this subject based on the ideXlab platform.
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Provocation of latent left ventricular outflow tract gradients with Amyl Nitrite and exercise in hypertrophic cardiomyopathy.
The American journal of cardiology, 1995Co-Authors: Thomas H. Marwick, Satoshi Nakatani, Brian Haluska, James D. Thomas, Harry M. LeverAbstract:Amyl Nitrite may be used to provoke latent gradients in patients with hypertrophic cardiomyopathy (HC) without significant resting outflow tract gradients, but afterload reduction may not be comparable to a more physiologic stressor such as symptom-limited exercise testing. This study compared the ability of Amyl Nitrite and exercise testing to provoke outflow tract gradients in 57 patients (40 men and 17 women, mean age +/- SD 49 +/- 16 years) with HC (septal thickness 19 +/- 5 mm, average resting gradient 13 +/- 10 mm Hg) who underwent echocardiography at rest, after Amyl Nitrite inhalation, and after maximal exercise. No significant gradient (< 50 mm Hg) was induced after either provocation in 26 patients (46%); in 15 patients (26%), inducibility was achieved after both stressors, in 6 (11%) after exercise only, and in 10 (18%) after Amyl only. Patients with Amyl-induced gradients differed from those in whom gradients were noninducible on the basis of smaller outflow tract dimensions (p < 0.001), larger resting gradients (p < 0.001), and a greater prevalence of "septal bulge" morphology (p = 0.02). Those with exercise-induced gradients were able to attain a greater workload (p = 0.07), have larger resting gradients (p = 0.02), and also tended to have a septal bulge morphology (p < or = 0.01). Although outflow tract obstruction increased to similar levels after Amyl Nitrite (49 +/- 39 mm Hg) and symptom-limited exercise (47 +/- 39 mm Hg), gradients induced by exercise and Amyl correlated poorly (r = 0.54).(ABSTRACT TRUNCATED AT 250 WORDS)
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763-5 Provocation of Latent Left Ventricular Outflow Tract Gradients with Amyl Nitrite and Exercise in Patients with Hypertrophic Cardiomyopathy
Journal of the American College of Cardiology, 1995Co-Authors: Thomas H. Marwick, Satoshi Nakatani, Brian Haluska, James D. Thomas, Harry M. LeverAbstract:In pts with hypertrophic cardiomyopathy (HCM) who have obstructive symptoms without significant resting outflow tract gradients, Amyl Nitrite may be used to provoke latent obstruction. However, the provocative effect of afterload reduction may not be comparable to a more physiologic method such as symptom-limited exercise stress testing. This study compared the ability of Amyl Nitrite and exercise testing to provoke outflow tract gradients in the same pts. Sixty-one pts (age 49 ± 17y, 43 male) with non-obstructive HCM (septal thickness 19 ± 5 mm, resting outflow tract gradient 15 ± 14 mmHg) underwent echocardiography at rest, following Amyl Nitrite inhalation, and after maximal exercise. Twenty-six pts (43%) remained without significant inducible gradients «50 mmHg) after either provocation, 17 (28%) became inducible after both stressors, 7 (11%) after exercise only, and 11 (18%) after Amyl only. Although obstruction increased to similar levels after Amyl Nitrite (50 ± 38 mmHg) and after symptom-limited exercise (49 ± 39 mmHg), gradients induced by exercise and Amyl correlated poorly (r = 0.54). Gradients were the same with both stressors in 15 patients (EO group), greater with exercise in 26 (EX group), and greater with Amyl in 20 patients (AM group). Differences between Amyl and exercise were unrelated to drug therapy. EQ(n = 15) EX(n = 26) AM (n = 20) p Age (ys) 37 ± 15 47 ± 17 61 ± 9 p l 0.001 EQ vs AM Septum (mm) 21 ± 5 20 ± 6 17 ± 3 p l 0.01 EQ vs AM Ex HR (% predicted) 73 ± 23 96 ± 9 82 ± 16 p l 0.001 EQ vs EX Exercise RPP (× 103) 21.4±8.2 33.9 ± 7.7 24.3 ± 85 p l 0.001 EQ vs EX Amyl gradient (mmHg) 40 ± 39 37 ± 33 76 ± 34 p l 0.001 EQ vs AM Ex gradient (mmHg) 40 ± 39 67 ± 42 33 ± 25 p l 0.03 EQ vs EX Conclusion Over 50% of pts with non-obstructive HCM at rest have inducible gradients which may explain inlermittent symptoms. Measurement of gradients after AM and EX should be included in the assessment of pts with HCM with suspected latent outflow obstruction. Pts with a preponderant AM response are older and have less hypertrophy. EX is particularly indicated in younger patients without AM-induced gradients.
Stavros Hadjimiltiades - One of the best experts on this subject based on the ideXlab platform.
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Dynamic changes in left ventricular outflow tract flow velocities after Amyl Nitrite inhalation in hypertrophic cardiomyopathy
American Heart Journal, 1991Co-Authors: Stavros Hadjimiltiades, Ioannis P. Panidis, Michael Mcallister, John Ross, Gary S. MintzAbstract:Abstract Doppler echocardiography was performed in 21 patients with hypertrophic cardiomyopathy (HC), in nine patients with no evidence of left ventricular (LV) hypertrophy by two-dimensional echocardiography, and in five patients with systemic hypertension and concentric LV hypertrophy. The LV outflow tract (LVOT) peak velocity was recorded by continuous wave Doppler technique at rest and after Amyl Nitrite inhalation. The LVOT pressure gradient was calculated by the modified Bernoulli equation. A significant increase in heart rate and a drop in systolic blood pressure were observed in all patients after Amyl Nitrite inhalation; no adverse effects were encountered. The peak LVOT velocity and pressure gradient increased significantly after provocation in all patients, but the increase was much more pronounced in patients with HC (peak LVOT velocity increased from 2.2 ± 0.8 to 4.3 ± 1.0 m/sec and peak gradient increased from 22 ± 17 to 78 ± 36 mm Hg). The Doppler spectral signal in patients with HC demonstrated a characteristic contour, with peak velocity occurring in late systole. However, the observed increase in LVOT peak velocity was not statistically different between treated (with β-blockers and calcium blockers) and untreated patients with HC. We conclude that LVOT peak velocity and pressure gradients in patients with HC can be readily assessed by Doppler echocardiography both at rest and after Amyl Nitrite inhalation. The dynamic changes in LVOT velocity induced by this provocation have certain characteristic features in obstructive HC but appear to be independent of the medical regimen used, at least in the dosages tested in our study.
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Dynamic changes in left ventricular outflow tract flow velocities after Amyl Nitrite inhalation in hypertrophic cardiomyopathy.
American heart journal, 1991Co-Authors: Stavros Hadjimiltiades, Ioannis P. Panidis, Michael Mcallister, John Ross, Gary S. MintzAbstract:Doppler echocardiography was performed in 21 patients with hypertrophic cardiomyopathy (HC), in nine patients with no evidence of left ventricular (LV) hypertrophy by two-dimensional echocardiography, and in five patients with systemic hypertension and concentric LV hypertrophy. The LV outflow tract (LVOT) peak velocity was recorded by continuous wave Doppler technique at rest and after Amyl Nitrite inhalation. The LVOT pressure gradient was calculated by the modified Bernoulli equation. A significant increase in heart rate and a drop in systolic blood pressure were observed in all patients after Amyl Nitrite inhalation; no adverse effects were encountered. The peak LVOT velocity and pressure gradient increased significantly after provocation in all patients, but the increase was much more pronounced in patients with HC (peak LVOT velocity increased from 2.2 +/- 0.8 to 4.3 +/- 1.0 m/sec and peak gradient increased from 22 +/- 17 to 78 +/- 36 mm Hg). The Doppler spectral signal in patients with HC demonstrated a characteristic contour, with peak velocity occurring in late systole. However, the observed increase in LVOT peak velocity was not statistically different between treated (with beta-blockers and calcium blockers) and untreated patients with HC. We conclude that LVOT peak velocity and pressure gradients in patients with HC can be readily assessed by Doppler echocardiography both at rest and after Amyl Nitrite inhalation. The dynamic changes in LVOT velocity induced by this provocation have certain characteristic features in obstructive HC but appear to be independent of the medical regimen used, at least in the dosages tested in our study.
Tsuneaki Surgimoto - One of the best experts on this subject based on the ideXlab platform.
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Effect of Amyl Nitrite on Mitral Valve Prolapse and Mitral Regurgitation: A Transesophageal Echocardiographic Study
American Journal of Noninvasive Cardiology, 1991Co-Authors: Katsu Takenaka, Tsuguya Sakamoto, Wataru Amano, Takahiro Shiota, Tsutomu Igarashi, Jun-ichi Suzuki, Tsuneaki SurgimotoAbstract:To test the hypothesis that Amyl Nitrite (AN) increases the degree of prolapse by reducing the left ventricular size and making the mitral apparatus relatively more redundant in patients with mitral valve prolapse (MVP), transesophageal echocardiography was performed in 23 patients with MPV before and after AN inhalation. The heart rate increased from 84±20 to 104±25 beats/min (p
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effect of Amyl Nitrite on mitral valve prolapse and mitral regurgitation a transesophageal echocardiographic study
American journal of noninvasive cardiology, 1991Co-Authors: Katsu Takenaka, Tsuguya Sakamoto, Wataru Amano, Takahiro Shiota, Tsutomu Igarashi, Jun-ichi Suzuki, Tsuneaki SurgimotoAbstract:To test the hypothesis that Amyl Nitrite (AN) increases the degree of prolapse by reducing the left ventricular size and making the mitral apparatus relatively more redundant in patients with mitral valve prolapse (MVP), transesophageal echocardiography was performed in 23 patients with MPV before and after AN inhalation. The heart rate increased from 84±20 to 104±25 beats/min (p<0.001), and the left ventricular end-diastolic dimension decreased from 40±6 to 37±5 mm (p<0.001) after AN administration
Thomas H. Marwick - One of the best experts on this subject based on the ideXlab platform.
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Provocation of latent left ventricular outflow tract gradients with Amyl Nitrite and exercise in hypertrophic cardiomyopathy.
The American journal of cardiology, 1995Co-Authors: Thomas H. Marwick, Satoshi Nakatani, Brian Haluska, James D. Thomas, Harry M. LeverAbstract:Amyl Nitrite may be used to provoke latent gradients in patients with hypertrophic cardiomyopathy (HC) without significant resting outflow tract gradients, but afterload reduction may not be comparable to a more physiologic stressor such as symptom-limited exercise testing. This study compared the ability of Amyl Nitrite and exercise testing to provoke outflow tract gradients in 57 patients (40 men and 17 women, mean age +/- SD 49 +/- 16 years) with HC (septal thickness 19 +/- 5 mm, average resting gradient 13 +/- 10 mm Hg) who underwent echocardiography at rest, after Amyl Nitrite inhalation, and after maximal exercise. No significant gradient (< 50 mm Hg) was induced after either provocation in 26 patients (46%); in 15 patients (26%), inducibility was achieved after both stressors, in 6 (11%) after exercise only, and in 10 (18%) after Amyl only. Patients with Amyl-induced gradients differed from those in whom gradients were noninducible on the basis of smaller outflow tract dimensions (p < 0.001), larger resting gradients (p < 0.001), and a greater prevalence of "septal bulge" morphology (p = 0.02). Those with exercise-induced gradients were able to attain a greater workload (p = 0.07), have larger resting gradients (p = 0.02), and also tended to have a septal bulge morphology (p < or = 0.01). Although outflow tract obstruction increased to similar levels after Amyl Nitrite (49 +/- 39 mm Hg) and symptom-limited exercise (47 +/- 39 mm Hg), gradients induced by exercise and Amyl correlated poorly (r = 0.54).(ABSTRACT TRUNCATED AT 250 WORDS)
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763-5 Provocation of Latent Left Ventricular Outflow Tract Gradients with Amyl Nitrite and Exercise in Patients with Hypertrophic Cardiomyopathy
Journal of the American College of Cardiology, 1995Co-Authors: Thomas H. Marwick, Satoshi Nakatani, Brian Haluska, James D. Thomas, Harry M. LeverAbstract:In pts with hypertrophic cardiomyopathy (HCM) who have obstructive symptoms without significant resting outflow tract gradients, Amyl Nitrite may be used to provoke latent obstruction. However, the provocative effect of afterload reduction may not be comparable to a more physiologic method such as symptom-limited exercise stress testing. This study compared the ability of Amyl Nitrite and exercise testing to provoke outflow tract gradients in the same pts. Sixty-one pts (age 49 ± 17y, 43 male) with non-obstructive HCM (septal thickness 19 ± 5 mm, resting outflow tract gradient 15 ± 14 mmHg) underwent echocardiography at rest, following Amyl Nitrite inhalation, and after maximal exercise. Twenty-six pts (43%) remained without significant inducible gradients «50 mmHg) after either provocation, 17 (28%) became inducible after both stressors, 7 (11%) after exercise only, and 11 (18%) after Amyl only. Although obstruction increased to similar levels after Amyl Nitrite (50 ± 38 mmHg) and after symptom-limited exercise (49 ± 39 mmHg), gradients induced by exercise and Amyl correlated poorly (r = 0.54). Gradients were the same with both stressors in 15 patients (EO group), greater with exercise in 26 (EX group), and greater with Amyl in 20 patients (AM group). Differences between Amyl and exercise were unrelated to drug therapy. EQ(n = 15) EX(n = 26) AM (n = 20) p Age (ys) 37 ± 15 47 ± 17 61 ± 9 p l 0.001 EQ vs AM Septum (mm) 21 ± 5 20 ± 6 17 ± 3 p l 0.01 EQ vs AM Ex HR (% predicted) 73 ± 23 96 ± 9 82 ± 16 p l 0.001 EQ vs EX Exercise RPP (× 103) 21.4±8.2 33.9 ± 7.7 24.3 ± 85 p l 0.001 EQ vs EX Amyl gradient (mmHg) 40 ± 39 37 ± 33 76 ± 34 p l 0.001 EQ vs AM Ex gradient (mmHg) 40 ± 39 67 ± 42 33 ± 25 p l 0.03 EQ vs EX Conclusion Over 50% of pts with non-obstructive HCM at rest have inducible gradients which may explain inlermittent symptoms. Measurement of gradients after AM and EX should be included in the assessment of pts with HCM with suspected latent outflow obstruction. Pts with a preponderant AM response are older and have less hypertrophy. EX is particularly indicated in younger patients without AM-induced gradients.