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Biomedical subjects

M S Gotsman

Publications and source records attributed to M S Gotsman.

At least 37 records · Page 2Linked to original sources
PubMed1998

New indicator for stent covering area.

A small gap between stent struts is essential to support the vessel wall, prevent elastic recoil, and prevent intimal flaps from prolpasing into the lumen. We defined Gap Index as the ratio of strut width divided by the percent of the vessel wall area covered by the stent metal, and proved mathematically that this index relates inversely to the total length of stent struts (or coil), and directly related to stent cell size. Twenty-four (12 tubular and 12 coil) stents from 17 manufacturers were analyzed. Strut width in the tubular and coil groups was 354.1 +/- 276.0 and 955.9 +/- 553.9 microm, respectively (P < 0.001). The relative metallic surface area (RMS) in the tubular and coil groups for 3 mm stent diameter was 16.0 +/- 4.6 and 10.6 +/- 3.7%, respectively (P < 0.005). Great variations in Gap Index were found amongst different stents, with up to 100-fold. Gap Index in the tubular and coil groups for 3 mm stent diameter was 24.4 +/- 21.7 and 105.8 +/- 97.5 units, respectively (P = 0.001). Thus, coil stents have a smaller relative metallic surface area despite increased strut width. This is the result of reduced total strut length and fewer and larger cells, as represented by a higher Gap Index. This information may be useful for new stents designs.

Biocompatible Materials↗
PubMed1998

Right atrial thrombi are related to indwelling central venous catheter position: insights into time course and possible mechanism of formation.

We studied the effect of central line catheters on thrombus formation in the right atrium (RA), including the incidence and echocardiographic characteristics of the catheter-associated thrombus as well as possible clinical implications in patients. We prospectively studied 55 patients by transesophageal echocardiography within 1 week after Hickman catheter implantation and on a follow-up study at 6 to 8 weeks. We succeeded in imaging the catheter tip in 48 of the 55 patients (87%). In the baseline study 13 had the tip placed in the RA, eight at the superior vena cava-atrium junction, and 27 in the superior vena cava. An abnormal mass, consistent with a thrombus, was found in 12.5% of the patients, all of which were seen within the 13-patient (46%) group with the Hickman catheter tip placed in the RA. Hickman catheter insertion is associated with high incidence (12.5%) of early formation of RA thrombus. The formation of these thrombi is asymptomatic and highly associated (p < 0.001) with the catheter tip position in the RA, in contrast to their positioning in the superior vena cava or in its junction with the right atrium. On the basis of these findings, we recommend that special attention and effort be given to placing of the catheter tip in the superior vena cava and avoiding the RA during the implantation procedure.

Adult↗
PubMed1998

Quantitative videodensitometric technique for verification of optimal coronary stent implantation.

Coronary angiography is not sensitive enough to define the results of stent implantation. Intravascular ultrasound defines accurately the anatomy of the vessel and the stent within the vessel and is thus considered the gold standard for defining the results of stent implantation. However intravascular ultrasound is an additional invasive procedure that is time consuming and expensive. This study describes a new simple quantitative videodensitometric technique, developed specifically to assess the results of stent implantation and compares the findings to intravascular ultrasound. In the proposed algorithm for the videodensitometric analysis, density profiles were constructed perpendicular to the long axis of the stented segment and each one was compared (after background subtraction) with a theoretic profile of a normal artery at that location. Density deficit index was determined at each point from the actual and theoretic profiles and a global volumetric density deficit index was calculated for each stent by integrating the deficit indices at all points along the stent. Similarly an area stenosis was determined at each point along the stent (using the stent and normal vessel cross sectional areas as defined by intravascular ultrasound) and the global volumetric stent stenosis was calculated by integrating the values of area stenosis along the stent. Twenty-five patients were evaluated immediately before and after coronary stent implantation. Global density deficit index improved from 66.1+/-16.4% before (after last balloon inflation) to 44.4+/-11.1% after stenting (P < 0.001). The shape of the curves of densitometric deficit indices along each stent were similar to the equivalent area stenosis curves as determined by intravascular ultrasound. The correlation (R = 0.74) between the global volumetric density deficit index and the global volumetric stent stenosis is statistically significant (P < 0.001). In conclusion, in this preliminary report we describe a new algorithm for videodensitometric analysis of the results of coronary stent implantation. As compared with intravascular ultrasound this method does not require an additional invasive procedure and it is quick cheap and easy to carry out.

Algorithms↗
PubMed1998

Diffuse narrowing of coronary arteries in diabetic patients: the earliest phase of coronary artery disease.

Coronary arteries in diabetic patients appear to be narrower than in normal subjects, but this has not been examined systematically. To investigate this hypothesis we reviewed the data of 711 consecutive patients with angiographically 'normal coronary arteries'. Excluded were patients with valvular, myocardial or pericardial disease, and patients with hypertension or hyperlipidemia. Thirteen diabetic patients (10 men) and 22 nondiabetic persons (8 men) constituted the study and control groups, respectively. The diameters of the coronary arteries and their branches were measured and adjusted for body surface area. The sum of the proximal left anterior descending (LAD), circumflex and right coronary arteries (RCA) was calculated and defined as total coronary diameter (TCD). The sum of the distal LAD, first diagonal, first marginal and distal RCA was calculated and defined as total distal coronary diameter (dTCD). The clinical data of both groups were comparable. Adjusted TCD for body surface area was 5.4 +/- 1.1 and 6.5 +/- 1.1 mm/m2 (p < 0.05) in diabetics and nondiabetics, respectively, and adjusted dTCD was 4.9 +/- 1.2 and 6.1 +/- 1.2 mm/m2 (p = 0.01) in diabetics and normal subjects, respectively. Specific arteries and branches that were significantly smaller in diabetics included: left main coronary artery, distal LAD, first diagonal, proximal RCA, distal RCA, right ventricular branch, and posterolateral and posterior descending artery of RCA origin. Gender was not a confounding factor since the control group had a larger proportion of women and still larger arteries than the diabetic group. In conclusion, coronary arteries and their branches in diabetic patients have smaller diameters than normal subjects. This may be due to increased coronary tone, diffuse mild atherosclerosis or both.

Coronary Angiography↗
PubMed1998

Coronary arteriovenous malformations in a patient with hereditary hemorrhagic telangiectasia--a case report.

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu) disease is characterized by cutaneous, mucosal, and visceral vascular anomalies. Two patients were previously described with coronary artery aneurysms (ectasia) associated with this disease. This report describes a patient with Osler-Weber-Rendu disease in whom multiple coronary arteriovenous malformations were identified during coronary angiography. The patient presented with anginal chest pain resulting from severe anemia. Upper gastrointestinal endoscopy revealed multiple angiodysplastic lesions throughout the esophagus and stomach.

Anemia, Iron-Deficiency↗
PubMed1997

The diameter of the epicardial coronary arteries in patients with dilated cardiomyopathy.

We investigated the diameter of epicardial coronary arteries in 12 patients (ten men) with dilated cardiomyopathy, and compared to 21 normal persons (14 men). Dilated cardiomyopathy patients were younger than controls with no difference in height, weight and body surface area. Ejection fraction was lower in dilated cardiomyopathy compared to normals (31+/-10% and 73+/-7%, respectively, P<0.001). Left ventricular mass was significantly larger (P=0.04). The sum of diameters of the proximal left anterior descending, circumflex and right coronary arteries (Total Coronary Diameter) in the dilated cardiomyopathy and controls was 13.4+/-2.7 and 10.5+/-1.5 mm (P<0.001). Absolute diameters of the left main, left anterior descending, circumflex, proximal right coronary artery and the right ventricular branch in dilated cardiomyopathy were also significantly larger as was Total Coronary Diameter adjusted for body surface area. Total Coronary Diameter adjusted for left ventricular mass, was significantly smaller (103.42+/-30.38, 146.00+/-41.59 mm/mg, respectively, P<0.03). Specific arteries in the dilated cardiomyopathy adjusted for left ventricular mass were significantly smaller, or had a tendency for smaller diameter compared to normals. There was no correlation between age and coronary diameter in each group. After adjusting for left ventricular mass there was no difference in coronary artery diameter between men and women. Thus, coronary arteries of patients with dilated cardiomyopathy have increased absolute diameter compared to normals, but decreased diameter when adjusted for left ventricular mass. This may contribute to patients' complaints and to the natural history of the disease.

Adult↗
PubMed1997

Long-term angiographic follow-up of coronary balloon angioplasty in patients with diabetes mellitus: a clue to the explanation of the results of the BARI study. Balloon Angioplasty Revascularization Investigation.

OBJECTIVES: We sought to compare the angiographic outcome of diabetic patients (treated with insulin or oral hypoglycemic agents) after successful coronary angioplasty with that in nondiabetic patients. The analysis included the outcome of the dilated (restenosis) and nondilated narrowings (disease progression). BACKGROUND: Recent data have confirmed that diabetes mellitus is an important risk factor for long-term adverse events. These adverse events are more common after balloon angioplasty than after bypass surgery (Bypass Angioplasty Revascularization Investigation [BARI]). METHODS: We examined retrospectively 353 coronary angiograms of 248 patients (55 diabetic, 193 nondiabetic) who were referred for diagnostic angiography >1 month after successful angioplasty (1.4 +/- 0.6 [mean +/- SD] repeat angiograms/patient). Restenosis and disease progression/regression were compared between groups by means of quantitative angiography. RESULTS: Baseline clinical and angiographic characteristics were similar in both groups. There was a nonsignificant trend for a higher restenosis rate of dilated narrowings in diabetic patients. There were no significant changes between diabetic and nondiabetic patients in the rates of progression and regression of narrowings that were not dilated during the initial angioplasty. The main difference was in the rate of appearance of new narrowings: There was a 22% increase in the number of narrowings on the follow-up angiogram in diabetic patients (38 new, 174 preexisting narrowings) compared with 12% (86 new, 734 preexisting narrowings) in nondiabetic patients (p < 0.004). Diabetes mellitus and the performance of angioplasty in the artery had an additive risk for development of new narrowings, which were identified in 15 (16.9%) of 89 arteries with and 16 (13.2%) of 121 without angioplasty in diabetic patients and in 42 (12.7%) of 331 arteries with and 38 (7.3%) of 518 without angioplasty in nondiabetic patients (p = 0.009). CONCLUSIONS: The combination of diabetes mellitus and an artery that was instrumented during balloon angioplasty is additive and increases the risk of formation of new narrowing in that artery. This finding may explain the high adverse event rates observed in diabetic patients in the angioplasty arm of the BARI study, most of whom had angioplasty performed in at least two arteries.

Aged↗
PubMed1997

Coronary angiographic characteristics of patients with permanent artificial pacemakers.

BACKGROUND: The cause of severe cardiac conduction disturbances is often uncertain. The aim of this study was to examine a group of patients with permanent pacemakers who underwent coronary arteriography to determine the extent of coronary atherosclerotic disease that might be responsible for the conduction disturbances. METHODS AND RESULTS: Forty-three consecutive patients with a permanent pacemaker and 36 matched control patients were investigated. The coronary angiographic study included measurement of diameter and stenosis severity, qualitative assessment of flow, and classification of pathological anatomy, particularly the blood supply to territories supplying the different segments of the conduction system. Among 43 patients with a permanent pacemaker, 27 had ischemic heart disease (17 after coronary artery bypass graft surgery). The conduction disturbance was infranodal in 28 patients, sinus nodal in 6, AV nodal in 4, and complete AV block of unspecified origin in 5. Patients with permanent pacemakers had a coronary artery pathology compromising blood flow to the septal branches and the right coronary artery (type IV anatomy). This pattern was significantly different from the matched control patients, in whom the most prevalent coronary anatomy was the combination of right coronary artery with distal left anterior descending artery (not involving the septal branches) lesions (P=.007). CONCLUSIONS: Patients with coronary artery disease and severe conduction disturbances that require implantation of permanent pacemakers are more likely to have a specific pathological coronary anatomy that combines a compromised blood flow to the septal branches of the left anterior descending artery with right coronary artery lesions. The location of lesions in the coronary tree rather than severe diffuse atherosclerosis appears to be responsible for the conduction disturbances.

Aged↗
PubMed1997

Changing paradigms in thrombolysis in acute myocardial infarction.

Acute myocardial infarction occurs when a ruptured coronary artery plaque causes sudden thrombotic occlusion of a coronary artery and cessation of coronary artery blood flow. This paper reviews the underlying coronary pathology in progressive coronary atherosclerosis, mechanisms of plaque rupture and arterial occlusion and the time relationship between coronary occlusion and myocardial necrosis. Reperfusion can be achieved by chemical thrombolysis with different thrombolytic agents. Early lysis is achieved best by prehospital administration, a transtelephonic monitor, a mobile intensive care unit, active general practitioner treatment or by warning the emergency room of impending arrival of a patient. Thrombolytic therapy may be unsuccessful and not achieve Grade III TIMI flow in less than 4 h (or even 2 h) due to inadequate or intermittent perfusion or reocclusion. Adjuvant therapy includes aspirin and platelet receptor antagonists. Bleeding is a constant danger. Direct percutaneous transluminal coronary angioplasty (PTCA) may be as effective or better than chemical thrombolysis. Reperfusion protects the myocardium and salvages viable tissue. It also improves mechanical remodelling of the ventricle. Long-term follow-up has shown that quantum leaps of fresh coronary occlusion causes step-wise progression in patient disability and that further early, prompt reperfusion can salvage myocardium and prevent this inexorable progress of the disease.

Fibrinolytic Agents↗
PubMed1997

Analysis of the onset and termination of repeated pattern ventricular arrhythmias.

A group of algorithms has been developed to investigate the characteristics of beat-to-beat intervals preceding and following the onset and termination of repeated pattern ventricular arrhythmias (RPVA) such as bigeminy and trigeminy. Eighty-five patients, each with more than 3000 ventricular ectopic beats in a 24-hour Holter recording and with more than 10 episodes of RPVA, were evaluated. A statistically significant prolongation of sinus intervals preceding the onset of bigeminy and trigeminy and shortening of postectopic intervals after the onset were observed. In addition, shortening of postectopic intervals before the termination of bigeminy and trigeminy and lengthening of sinus intervals following their termination were also seen. A significant presence of these characteristics was not observed in arrhythmias with a greater number of sinus beats between ectopic beats. These dynamics provide information which may be utilized in the assessment of mechanisms involved in the onset and termination of RPVA.

Algorithms↗
PubMed1997

Atherosclerosis studies by intracoronary ultrasound.

Intravascular ultrasound (IVUS) is a new technique of tomographic visualization of the coronary arteries: its lumen, wall and pathology. Three dimensional (3D) reconstruction shows the tubular structure of the arterial wall and its pathology. IVUS has many advantages over coronary angiography: it has better resolution and shows many hidden lesions. IVUS has helped uncover the underlying mechanisms of percutaneous transluminal coronary angioplasty (PTCA), restenosis, the use and value of other interventional techniques such as directional coronary atherectomy (DCA), rotational atherectomy and stent implantation, and has great value in planning complex interventional procedures. The new American Heart Association (AHA) classification of coronary atherosclerosis pathology can be demonstrated by IVUS. IVUS is sensitive for studies of atheroma regression and progression and shows the coronary artery lesions after cardiac transplantation.

Animals↗
PubMed1997

Initial experience with long coronary stents: the changing practice of coronary angioplasty.

The initial experience with the use of long coronary stents (> 30 mm in length) was analyzed retrospectively. Sixty-seven stents were deployed in 58 narrowings in 57 patients (34 AVE Microstents, 16 Nir stents, four Gianturco-Roubin II stents, and 13 Wallstents). Stents were implanted in 22 patients with unstable angina, 34 patients with stable angina, and one patient during direct angioplasty for acute myocardial infarction. Eighteen additional short stents were implanted to cover the entire length of the lesions so that an average of one and a half stents were deployed per patient. The length of the narrowings before stenting was 40 +/- 20 mm and the length of the stented segments was 45 +/- 20 mm. Stents were deployed for "bailout" in 23 narrowings, to improve suboptimal results of balloon angioplasty in 18 narrowings, and electively in 17 narrowings. Twenty of the 67 long stents were deployed in saphenous vein grafts. The success rate of stent implantation was 100%. One patient had a rupture of a saphenous vein graft after deployment of two long stents, with tamponade treated by emergency surgery. One patient had chest pain 18 hours after stent deployment; by the time he arrived at the catheterization laboratory the pain had subsided and the angiogram revealed a patent artery with normal flow. There were no other major complications during the hospital course and 1-month follow-up. We conclude that long coronary stents can be deployed successfully in native coronary arteries and vein grafts. They are useful for elective implantation and extremely helpful in bailout situations. The immediate results are excellent, but long-term outcome is awaited.

Aged↗
PubMed1997

Angiographic deterioration of target coronary artery narrowing as a result of percutaneous balloon angioplasty.

We evaluated the long-term angiographic outcome of balloon angioplasty by comparing original and follow-up target coronary narrowing. Rather than using restenosis to determine outcome, as in most angioplasty studies, we took an unusual approach and analyzed outcome in terms that are commonly used in progression and regression studies after medical interventions. Quantitative angiographic measurements were undertaken in 315 narrowings with an initial diameter stenosis <90% before and after angioplasty and at follow-up. Angiographic deterioration (>10% increase in follow-up diameter stenosis) was identified in 44 (14%) narrowings. Angiographic deterioration was not influenced by age, sex, risk factors, lipid profile, or the indication for angioplasty. Deterioration was also not predicted by the severity, length, or the location of the narrowing. The deteriorating narrowings had a higher recoil after dilatation compared with narrowings with angiographic improvement (21% +/- 31% vs 12% +/- 17%, p = 0.006); the residual stenosis after angioplasty was therefore higher. The late loss was also significantly increased compared with narrowings with angiographic improvement (65% +/- 26% vs 8% +/- 24%, p < 0.001). We conclude that the incidence of angiographic deterioration of coronary disease as a result of restenosis is uncommon but not negligible. Interventional cardiologists should resist the temptation to dilate mild, silent coronary narrowings because the procedure might have an unfavorable angiographic (and probably clinical) effect.

Angioplasty, Balloon, Coronary↗
PubMed1997

The ongoing influence of staff training on the performance of radiofrequency catheter ablation.

The aim of this study was to assess whether the performance of RF catheter ablations continues to improve by further staff training once an initial success rate of > 90% has been achieved. Two hundred and ninety-five procedures of SVT catheter ablation using RF energy were studied. Atrial tachycardia and atrial flutter substrate ablations were not included. The procedures were performed during a 4-year period by the same physician and nurse, who had previous training in these procedures. The 4-year period was subdivided into four consecutive 1-year periods in which 69, 72, 68, and 86 procedures were performed. The outcome, recurrence rate, and duration of the curative procedure were compared among the four periods. There was no significant difference in the initial success rate among the four periods. The recurrence rate decreased from 21.74% to 13.95% (P < 0.05). The duration of the curative procedure decreased from 93.7 +/- 78.4 minutes to 39.1 +/- 32.2 minutes (P < 0.001), and the fluoroscopic time decreased from 25.5 +/- 22.3 minutes to 11.3 +/- 8.2 minutes (P < 0.001). These results were similar when accessory pathway and selective AV nodal pathways ablations were separately evaluated. Following the initial staff training, during which the expected 80%-90% success rate is achieved, additional training will reduce the recurrence rate and the duration of the procedures at a similar level of success.

Adult↗
PubMed1996

Experience with the AVE Micro stent in native coronary arteries.

Experience with implantation of 62 AVE Micro stents is described. Stents were quickly and successfully deployed in 62 of 63 attempts (98.4%), in tortuous coronary vessels, through proximally deployed stents, and under conditions of hemodynamic instability. It is therefore a very attractive choice to treat difficult anatomy during urgent situations.

Aged↗
PubMed1996

"Congenital" coronary arteriovenous malformations: are they truly congenital?

We report a patient with ischemic chest pain due to obstructive coronary artery disease. The patient underwent a second cardiac catheterization 2 years later that revealed progression of the coronary disease and the appearance of a new arteriovenous malformation. Unless a prior angiogram was available, this malformation would have been classified as congenital. This case report raises the question of whether all congenital arteriovenous malformations are truly congenital.

Aged↗