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Papers by Hylton Miller
Ultrasound Angioplasty Using the Angiosonics System
Developments in Cardiovascular Medicine, 1996
The development of transluminal balloon angioplasty has significantly modified the therapeutic ap... more The development of transluminal balloon angioplasty has significantly modified the therapeutic approach to obstructive coronary [1,2] and peripheral arterial disease [3], Despite overall favorable results with balloon angioplasty, this technique sustains several limitations. These include a relatively limited success rate in complex vascular lesions (eccentric, thrombus-rich, calcified, long, or ostial lesions), acute complications (thrombosis, dissection, and vascular spasm), and the long-term complication of vascular restenosis. Alternative angioplasty techniques have been developed in the past few years in an attempt to resolve these issues (e.g., directional and rotational atherectomy, laser angioplasty, and vascular stents). Still, their role in transluminal angioplasty has yet to be fully defined.
Recent evidence suggests that atherosclerosis is an inflammatory disorder in which cytokines appe... more Recent evidence suggests that atherosclerosis is an inflammatory disorder in which cytokines appear to play an important role. Special attention centered over the possible contribution of cytokines to the destabilization of the plaque. IL-18 is a proinflammatory cytokine of the IL-1 family, recognized for its ability to promote IFN-gamma secretion. It has recently been detected in human plaques and its administration was associated with increased atherosclerosis in apolipoprotein E (apoE) mice concomitant with an increase in plaque infiltrating inflammatory cells. In our study, we investigated whether patients with established atherosclerosis, with either stable or unstable angina, possessed high levels of IL-18. Patients with stable angina (n=48) were from the outpatient clinic whereas patients with unstable angina (n=73) were recruited upon admission and prior to performance of coronary angiography. Control patients (n=19) were healthy subjects with no evidence of coronary artery ...
Plaque Size and Composition in Apolipoprotein E Knockout Mice Transfer of Endothelial Progenitor and Bone Marrow Cells Influences Atherosclerotic
Jacob George, Arnon Afek, Anastasia Abashidze, Haim Shmilovich, Varda Deutsch, Juri Plaque Size a... more Jacob George, Arnon Afek, Anastasia Abashidze, Haim Shmilovich, Varda Deutsch, Juri Plaque Size and Composition in Apolipoprotein E Knockout Mice Transfer of Endothelial Progenitor and Bone Marrow Cells Influences Atherosclerotic Print ISSN: 1079-5642. Online ISSN: 1524-4636 Copyright © 2005 American Heart Association, Inc. All rights reserved. Greenville Avenue, Dallas, TX 75231 is published by the American Heart Association, 7272 Arteriosclerosis, Thrombosis, and Vascular Biology doi: 10.1161/01.ATV.0000188554.49745.9e 2005; 2005;25:2636-2641; originally published online September 29, Arterioscler Thromb Vasc Biol. http://atvb.ahajournals.org/content/25/12/2636 World Wide Web at: The online version of this article, along with updated information and services, is located on the
Clinical and inflammatory effects of dietary ?-arginine in patients with intractable angina pectoris
Amer J Cardiol, 1999
Assessment of coronary reserve in man?
Amer J Cardiol, 1976
Anomalous Origin of the Right Coronary Artery from the Ascending Aorta
Cardiology, 1987
Catheterization and Cardiovascular Diagnosis, 1995
The purpose of this work was to examine in vivo the safety of sonication in the coronary arteries... more The purpose of this work was to examine in vivo the safety of sonication in the coronary arteries in a live animal model. In intact dogs (n =8), balloon dilatation was performed on the proximal left anterior descending artery (LAD) followed by sonication to the left circumflex artery (LCX) in power levels found to be optimal for thrombus ablation. Postdilatation and post-ultrasound coronary angiography, echocardiography, histopathology, CK-MB, indices of hemolysis, and coagulation were compared. Sonication did not induce changes in the ECG or blood pressure. Coronary angiography revealed no adverse side effects or change in arterial diameter (2.3 f 0.7 vs. 2.4 f 0.3 mm). Echocardiography showed transient opacification of the myocardium. Histopathology revealed a comparable minimal degree of endothelial denudation. After sonication there were no changes in the level of CK-MB (312 f 168 vs. 283 f 207 IU), hemoglobin (11.3 I-0.9 vs. 12.7 k 1.1 gr%), haptoglobin (479 f 136 vs. 451 ? 121 mg/dL), fibrinogen (142 f 18 vs. 165 f 28 mg%), partial thromboplastin time (17.3 f 3.2 vs. 17.6 2 3.4 sec), prothrombin time (13.3 f 7.8 vs. 11.5 f 2.9 sec), and degree of platelet aggregation (55 f 17 vs. 62 f 8%). Thus, the data suggest that transluminal coronary sonication exerts no overt adverse effects in vivo.
Conjoined Double Internal Mammary Artery Grafting
Scandinavian Cardiovascular Journal, 1994
Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patien... more Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patients. In ten of them one IMA was used as a free graft, and was proximally connected to the other ("conjoined" double IMA), the indications being insufficient supply of adequate veins, diseased aortic wall, availability of only a short right IMA segment for free grafting, occluded left subclavian artery, and when distal and scattered lesions of relatively important vessels had to be bypassed. Additional sequential IMA anastomoses were performed in four patients and an additional sequential vein graft in a fifth. All patients became angina-free postoperatively and have remained so during observation up to 16 months. Recatheterization studies were performed in six patients and in all of them the IMA-to-IMA (n = 6) and distal anastomoses (n = 26) were patent. Conjoined double IMA grafting is an important option available to the cardiac surgeon for management of selected patients with coronary artery disease.
Journal of the American College of Cardiology, 2002
12 pts). Group 2: FFRti.75 (44 pts). Results: In pts with reduced FFR (group 1) LAminr4.0 mm2 was... more 12 pts). Group 2: FFRti.75 (44 pts). Results: In pts with reduced FFR (group 1) LAminr4.0 mm2 was obtained in 3 pts (25%). Moreover, LAminc4.0 mm'was present in 16 pts (38%) despite of FFRa0.75 (group 2). The comparison of QCA, FFR and ICUS parameters between the two groups is shown in table. Conclusions: ICUS assessment of the minimal luminal cross-sectional area has only a limited value in determining the clinical importance of intermediate coronary lesion. Other factors, such as lesion length may also influence functional severity of intermediate coronary lesion.
Journal of the American College of Cardiology, 1996
Physiologic assessment of serial lesions: Comparison of present methodologies
Journal of the American College of Cardiology, 2003
Поиск в библиотеке, Расширенный поиск. ...
Journal of the American College of Cardiology, 2004
S-Vascular Disease, Hypertension, and Prevention 489A Vascular Disease, Hypertension, and Prevent... more S-Vascular Disease, Hypertension, and Prevention 489A Vascular Disease, Hypertension, and Prevention mary endpoint of target vessel revascularization (TVR) was reached in 63 (13.9%) patients. Several polymorphisms seem to play a role in the restenotic process. So far we identified an association between interleukin 4 (p=0.026) and three polymorphisms in the adrenergic beta-2 receptor (p=0.064,0.011,0.077) and TVR. Also cytotoxic T-lymphocyteassociated protein 4 seems to be associated with TVR (p=0.032) More genotyping is being performed at this moment. Conclusion: Several polymorphisms seem to play a role in the restenotic process in patients with diabetes mellitus. Interleukin 4, cytotoxic T-lymphocyte-associated protein 4 and adrenergic beta-2 receptor seem to be three important genes in the process of restenosis in diabetics. This can lead to a better risk stratification and to a more tailored therapy for diabetic patients to prevent restenosis after PTCA.
Annual Review of Medicine, 2001
▪ Heart failure is a complex neurohumoral and inflammatory syndrome. Recent studies have shown ... more ▪ Heart failure is a complex neurohumoral and inflammatory syndrome. Recent studies have shown that proinflammatory cytokines (interleukin-1, interleukin-2, interleukin-6, interleukin-10, and tumor necrosis factor) are involved in cardiac depression and in the complex syndrome of heart failure. Understanding the involvement of these cytokines may enable us to reverse cardiac depression and heart failure by the use of monoclonal antibodies directed against specific cytokines to block the downhill progression of heart failure.
Journal of Thrombosis and Thrombolysis, 1998
This series included 26 patients with acute myocardial infarction (15 patients) or unstable angin... more This series included 26 patients with acute myocardial infarction (15 patients) or unstable angina (11 patients), with thrombotic lesions identified by angiography and treated with intravenous heparin (mean 8 ± 3 days, aPTT 1.5–2.5 times baseline) and aspirin (250 mg/day). A quantitative angiographic analysis was performed, and comparison of the lesion morphology before and after the antithrombotic treatment was conducted,
Catheter ablation of incessant ventricular tachycardia refractory to external cardioversions
The American Journal of Cardiology, 1985
Percutaneous Transluminal Coronary Angioplasty of an Anomalous Right Coronary Artery Arising from a Separate Ostium in the Left Sinus of Valsalva: A Case Report
Angiology, 1995
BMJ, 1996
Objective-To test the hypothesis that subjects who clear chylomicron remnants slowly from plasma ... more Objective-To test the hypothesis that subjects who clear chylomicron remnants slowly from plasma may be at higher risk of coronary artery disease than indicated by their fasting plasma lipid concentrations.
American Journal of Cardiology, 1984
American Journal of Cardiology, 1994
Ultrasound angioplasty is a newly developed technology for percutaneous arterial recanaliza tion.... more Ultrasound angioplasty is a newly developed technology for percutaneous arterial recanaliza tion. Data suggest that ultrasound is particularly effective in ablating fresh thrombi. Arterial walls were found to be resistant to ultrasound abla tion. Thrombi, aortic wall segments, and hydroxyproline gelatin were studied in vitro to determine their respective ablation rates. The elasticity of the samples was determined in a force-mode apparatus. The cavitation threshold was determined in an arterial phantom apparatus. Thrombi displayed ablation rates that were r20 times higher than those of aortic wall samples (591 rfs 82 vs 25 -e 14 mg/s, p ~0.001). The diierences in ablation rates were accompanied by signlficantly lower elasticities in the thrombus group compared with those in the aortic wall group (0.15 + 0.05 vs 312 f 37 g/cm2, p ~0.001). Experiments with hydroxyproline gelatin suggest a negative correlation (r = -0.90) between elasticity and ultrasound ablation. Ultrasound ablation of thrombi was evident only above the cavitatlon threshold. Thus, ultrasound angioplasty has the potential to induce the selective injury required for successful transluminal intervention in the treatment of thrombus-tich lesions. U ltrasound angioplasty is a new technology developed for percutaneous arterial recanalization. In this method the arterial occlusion is ablated by application of high-intensity low-frequency ultrasound delivered by a dedicated device. We have previously reported our experience with ultrasound angioplasty in experimental settings both in vitro and in viva,' together with clinical experience in peripheral vascular disease.2 The data suggested that ultrasound is particularly effective in ablating fresh thrombi. Arterial walls were found to be resistant to ultrasound ablation. The selective ablation of fresh clots by this technology makes it a potentially effective and safe method for treating thrombusrich lesions. The mechanism that effects the ablation of thrombi by ultrasound and its selectivity has not been studied to date. The objectives of this study were to test the hypotheses that the cavitation effect plays an important role in the mechanism of "ultrasound thrombolysis" and that ablation rates correlate with the elasticities of the occlusive thrombus and the arterial wa11.2 METHODS Ultrasound angioplasty device: An ultrasound angioplasty device for peripheral application (Angiosonits, Wayne, New Jersey) was described in detail elsewhere.2 Briefly, the device consists of a flexible, 1.6 mm diameter, ultrasound catheter mechanically coupled at its proximal end to an ultrasound transducer. The transducer consists of piezoelectric crystals that convert electrical energy to high-power ultrasonic energy at 20 kHz. The ultrasonic energy is transmitted by the ultrasound catheter to the target lesion in the arterial system. The ultrasound angioplasty device was operated in the pulsed mode with a 50% duty cycle. The duration of the pulse was 0.5 second, with an interval of 0.5 second. The device has an adjustable power output ranging from 5 to 100 W, with a distal tip longitudinal displacement range of 48 to 100 p,.
Journal of Electrocardiology, 1986
The ability to detect coronary artery disease (CAD) in patients with normal, conventional electro... more The ability to detect coronary artery disease (CAD) in patients with normal, conventional electrocardiograms (ECG) was studied using high frequency electrocardiography and an advanced method of signal averaging in three groups of subjects. Group A con' sisted of ten healthy subjects under the age of 30; Group B of 15 patients with chest pains and normal coronary arteries; and Group C of 20patients with chest pains and CAD. Four hundred ECG waveforms from leads V s ' V 4 and V 5 were recorded, and the recorded analog data were digitized. The digitized waveforms were averaged using a crosscorrelation function which operates in the frequency domain (fast·Fourier transform algorithm). The signals were filtered with a digital band pUBS filter with 150and 250Hz low and high cut-off frequencies, respectively. Zones of reduced amplitude in the envelope of the filtered QRS complex of at least two precordial leads were found more significantly in patients with CAD (75%) than in patients without CAD (12% for Groups A and B, p <0.00003). However, no significant difference was found between the voltage over the high frequency QRS complex and that of its envelope between the three groups.
Ultrasound Angioplasty Using the Angiosonics System
Developments in Cardiovascular Medicine, 1996
The development of transluminal balloon angioplasty has significantly modified the therapeutic ap... more The development of transluminal balloon angioplasty has significantly modified the therapeutic approach to obstructive coronary [1,2] and peripheral arterial disease [3], Despite overall favorable results with balloon angioplasty, this technique sustains several limitations. These include a relatively limited success rate in complex vascular lesions (eccentric, thrombus-rich, calcified, long, or ostial lesions), acute complications (thrombosis, dissection, and vascular spasm), and the long-term complication of vascular restenosis. Alternative angioplasty techniques have been developed in the past few years in an attempt to resolve these issues (e.g., directional and rotational atherectomy, laser angioplasty, and vascular stents). Still, their role in transluminal angioplasty has yet to be fully defined.
Recent evidence suggests that atherosclerosis is an inflammatory disorder in which cytokines appe... more Recent evidence suggests that atherosclerosis is an inflammatory disorder in which cytokines appear to play an important role. Special attention centered over the possible contribution of cytokines to the destabilization of the plaque. IL-18 is a proinflammatory cytokine of the IL-1 family, recognized for its ability to promote IFN-gamma secretion. It has recently been detected in human plaques and its administration was associated with increased atherosclerosis in apolipoprotein E (apoE) mice concomitant with an increase in plaque infiltrating inflammatory cells. In our study, we investigated whether patients with established atherosclerosis, with either stable or unstable angina, possessed high levels of IL-18. Patients with stable angina (n=48) were from the outpatient clinic whereas patients with unstable angina (n=73) were recruited upon admission and prior to performance of coronary angiography. Control patients (n=19) were healthy subjects with no evidence of coronary artery ...
Plaque Size and Composition in Apolipoprotein E Knockout Mice Transfer of Endothelial Progenitor and Bone Marrow Cells Influences Atherosclerotic
Jacob George, Arnon Afek, Anastasia Abashidze, Haim Shmilovich, Varda Deutsch, Juri Plaque Size a... more Jacob George, Arnon Afek, Anastasia Abashidze, Haim Shmilovich, Varda Deutsch, Juri Plaque Size and Composition in Apolipoprotein E Knockout Mice Transfer of Endothelial Progenitor and Bone Marrow Cells Influences Atherosclerotic Print ISSN: 1079-5642. Online ISSN: 1524-4636 Copyright © 2005 American Heart Association, Inc. All rights reserved. Greenville Avenue, Dallas, TX 75231 is published by the American Heart Association, 7272 Arteriosclerosis, Thrombosis, and Vascular Biology doi: 10.1161/01.ATV.0000188554.49745.9e 2005; 2005;25:2636-2641; originally published online September 29, Arterioscler Thromb Vasc Biol. http://atvb.ahajournals.org/content/25/12/2636 World Wide Web at: The online version of this article, along with updated information and services, is located on the
Clinical and inflammatory effects of dietary ?-arginine in patients with intractable angina pectoris
Amer J Cardiol, 1999
Assessment of coronary reserve in man?
Amer J Cardiol, 1976
Anomalous Origin of the Right Coronary Artery from the Ascending Aorta
Cardiology, 1987
Catheterization and Cardiovascular Diagnosis, 1995
The purpose of this work was to examine in vivo the safety of sonication in the coronary arteries... more The purpose of this work was to examine in vivo the safety of sonication in the coronary arteries in a live animal model. In intact dogs (n =8), balloon dilatation was performed on the proximal left anterior descending artery (LAD) followed by sonication to the left circumflex artery (LCX) in power levels found to be optimal for thrombus ablation. Postdilatation and post-ultrasound coronary angiography, echocardiography, histopathology, CK-MB, indices of hemolysis, and coagulation were compared. Sonication did not induce changes in the ECG or blood pressure. Coronary angiography revealed no adverse side effects or change in arterial diameter (2.3 f 0.7 vs. 2.4 f 0.3 mm). Echocardiography showed transient opacification of the myocardium. Histopathology revealed a comparable minimal degree of endothelial denudation. After sonication there were no changes in the level of CK-MB (312 f 168 vs. 283 f 207 IU), hemoglobin (11.3 I-0.9 vs. 12.7 k 1.1 gr%), haptoglobin (479 f 136 vs. 451 ? 121 mg/dL), fibrinogen (142 f 18 vs. 165 f 28 mg%), partial thromboplastin time (17.3 f 3.2 vs. 17.6 2 3.4 sec), prothrombin time (13.3 f 7.8 vs. 11.5 f 2.9 sec), and degree of platelet aggregation (55 f 17 vs. 62 f 8%). Thus, the data suggest that transluminal coronary sonication exerts no overt adverse effects in vivo.
Conjoined Double Internal Mammary Artery Grafting
Scandinavian Cardiovascular Journal, 1994
Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patien... more Double internal mammary artery (IMA) grafting to the coronary arteries was performed on 82 patients. In ten of them one IMA was used as a free graft, and was proximally connected to the other ("conjoined" double IMA), the indications being insufficient supply of adequate veins, diseased aortic wall, availability of only a short right IMA segment for free grafting, occluded left subclavian artery, and when distal and scattered lesions of relatively important vessels had to be bypassed. Additional sequential IMA anastomoses were performed in four patients and an additional sequential vein graft in a fifth. All patients became angina-free postoperatively and have remained so during observation up to 16 months. Recatheterization studies were performed in six patients and in all of them the IMA-to-IMA (n = 6) and distal anastomoses (n = 26) were patent. Conjoined double IMA grafting is an important option available to the cardiac surgeon for management of selected patients with coronary artery disease.
Journal of the American College of Cardiology, 2002
12 pts). Group 2: FFRti.75 (44 pts). Results: In pts with reduced FFR (group 1) LAminr4.0 mm2 was... more 12 pts). Group 2: FFRti.75 (44 pts). Results: In pts with reduced FFR (group 1) LAminr4.0 mm2 was obtained in 3 pts (25%). Moreover, LAminc4.0 mm'was present in 16 pts (38%) despite of FFRa0.75 (group 2). The comparison of QCA, FFR and ICUS parameters between the two groups is shown in table. Conclusions: ICUS assessment of the minimal luminal cross-sectional area has only a limited value in determining the clinical importance of intermediate coronary lesion. Other factors, such as lesion length may also influence functional severity of intermediate coronary lesion.
Journal of the American College of Cardiology, 1996
Physiologic assessment of serial lesions: Comparison of present methodologies
Journal of the American College of Cardiology, 2003
Поиск в библиотеке, Расширенный поиск. ...
Journal of the American College of Cardiology, 2004
S-Vascular Disease, Hypertension, and Prevention 489A Vascular Disease, Hypertension, and Prevent... more S-Vascular Disease, Hypertension, and Prevention 489A Vascular Disease, Hypertension, and Prevention mary endpoint of target vessel revascularization (TVR) was reached in 63 (13.9%) patients. Several polymorphisms seem to play a role in the restenotic process. So far we identified an association between interleukin 4 (p=0.026) and three polymorphisms in the adrenergic beta-2 receptor (p=0.064,0.011,0.077) and TVR. Also cytotoxic T-lymphocyteassociated protein 4 seems to be associated with TVR (p=0.032) More genotyping is being performed at this moment. Conclusion: Several polymorphisms seem to play a role in the restenotic process in patients with diabetes mellitus. Interleukin 4, cytotoxic T-lymphocyte-associated protein 4 and adrenergic beta-2 receptor seem to be three important genes in the process of restenosis in diabetics. This can lead to a better risk stratification and to a more tailored therapy for diabetic patients to prevent restenosis after PTCA.
Annual Review of Medicine, 2001
▪ Heart failure is a complex neurohumoral and inflammatory syndrome. Recent studies have shown ... more ▪ Heart failure is a complex neurohumoral and inflammatory syndrome. Recent studies have shown that proinflammatory cytokines (interleukin-1, interleukin-2, interleukin-6, interleukin-10, and tumor necrosis factor) are involved in cardiac depression and in the complex syndrome of heart failure. Understanding the involvement of these cytokines may enable us to reverse cardiac depression and heart failure by the use of monoclonal antibodies directed against specific cytokines to block the downhill progression of heart failure.
Journal of Thrombosis and Thrombolysis, 1998
This series included 26 patients with acute myocardial infarction (15 patients) or unstable angin... more This series included 26 patients with acute myocardial infarction (15 patients) or unstable angina (11 patients), with thrombotic lesions identified by angiography and treated with intravenous heparin (mean 8 ± 3 days, aPTT 1.5–2.5 times baseline) and aspirin (250 mg/day). A quantitative angiographic analysis was performed, and comparison of the lesion morphology before and after the antithrombotic treatment was conducted,
Catheter ablation of incessant ventricular tachycardia refractory to external cardioversions
The American Journal of Cardiology, 1985
Percutaneous Transluminal Coronary Angioplasty of an Anomalous Right Coronary Artery Arising from a Separate Ostium in the Left Sinus of Valsalva: A Case Report
Angiology, 1995
BMJ, 1996
Objective-To test the hypothesis that subjects who clear chylomicron remnants slowly from plasma ... more Objective-To test the hypothesis that subjects who clear chylomicron remnants slowly from plasma may be at higher risk of coronary artery disease than indicated by their fasting plasma lipid concentrations.
American Journal of Cardiology, 1984
American Journal of Cardiology, 1994
Ultrasound angioplasty is a newly developed technology for percutaneous arterial recanaliza tion.... more Ultrasound angioplasty is a newly developed technology for percutaneous arterial recanaliza tion. Data suggest that ultrasound is particularly effective in ablating fresh thrombi. Arterial walls were found to be resistant to ultrasound abla tion. Thrombi, aortic wall segments, and hydroxyproline gelatin were studied in vitro to determine their respective ablation rates. The elasticity of the samples was determined in a force-mode apparatus. The cavitation threshold was determined in an arterial phantom apparatus. Thrombi displayed ablation rates that were r20 times higher than those of aortic wall samples (591 rfs 82 vs 25 -e 14 mg/s, p ~0.001). The diierences in ablation rates were accompanied by signlficantly lower elasticities in the thrombus group compared with those in the aortic wall group (0.15 + 0.05 vs 312 f 37 g/cm2, p ~0.001). Experiments with hydroxyproline gelatin suggest a negative correlation (r = -0.90) between elasticity and ultrasound ablation. Ultrasound ablation of thrombi was evident only above the cavitatlon threshold. Thus, ultrasound angioplasty has the potential to induce the selective injury required for successful transluminal intervention in the treatment of thrombus-tich lesions. U ltrasound angioplasty is a new technology developed for percutaneous arterial recanalization. In this method the arterial occlusion is ablated by application of high-intensity low-frequency ultrasound delivered by a dedicated device. We have previously reported our experience with ultrasound angioplasty in experimental settings both in vitro and in viva,' together with clinical experience in peripheral vascular disease.2 The data suggested that ultrasound is particularly effective in ablating fresh thrombi. Arterial walls were found to be resistant to ultrasound ablation. The selective ablation of fresh clots by this technology makes it a potentially effective and safe method for treating thrombusrich lesions. The mechanism that effects the ablation of thrombi by ultrasound and its selectivity has not been studied to date. The objectives of this study were to test the hypotheses that the cavitation effect plays an important role in the mechanism of "ultrasound thrombolysis" and that ablation rates correlate with the elasticities of the occlusive thrombus and the arterial wa11.2 METHODS Ultrasound angioplasty device: An ultrasound angioplasty device for peripheral application (Angiosonits, Wayne, New Jersey) was described in detail elsewhere.2 Briefly, the device consists of a flexible, 1.6 mm diameter, ultrasound catheter mechanically coupled at its proximal end to an ultrasound transducer. The transducer consists of piezoelectric crystals that convert electrical energy to high-power ultrasonic energy at 20 kHz. The ultrasonic energy is transmitted by the ultrasound catheter to the target lesion in the arterial system. The ultrasound angioplasty device was operated in the pulsed mode with a 50% duty cycle. The duration of the pulse was 0.5 second, with an interval of 0.5 second. The device has an adjustable power output ranging from 5 to 100 W, with a distal tip longitudinal displacement range of 48 to 100 p,.
Journal of Electrocardiology, 1986
The ability to detect coronary artery disease (CAD) in patients with normal, conventional electro... more The ability to detect coronary artery disease (CAD) in patients with normal, conventional electrocardiograms (ECG) was studied using high frequency electrocardiography and an advanced method of signal averaging in three groups of subjects. Group A con' sisted of ten healthy subjects under the age of 30; Group B of 15 patients with chest pains and normal coronary arteries; and Group C of 20patients with chest pains and CAD. Four hundred ECG waveforms from leads V s ' V 4 and V 5 were recorded, and the recorded analog data were digitized. The digitized waveforms were averaged using a crosscorrelation function which operates in the frequency domain (fast·Fourier transform algorithm). The signals were filtered with a digital band pUBS filter with 150and 250Hz low and high cut-off frequencies, respectively. Zones of reduced amplitude in the envelope of the filtered QRS complex of at least two precordial leads were found more significantly in patients with CAD (75%) than in patients without CAD (12% for Groups A and B, p <0.00003). However, no significant difference was found between the voltage over the high frequency QRS complex and that of its envelope between the three groups.