Biomedical subjects

K Khalife

Publications and source records attributed to K Khalife.

At least 19 recordsLinked to original sources

PubMed2001

Stent placement compared with balloon angioplasty for small coronary arteries: in-hospital and 6-month clinical and angiographic results.

BACKGROUND: Stenting has been demonstrated to be superior to balloon angioplasty in de novo focal lesions located in large native vessels. However, in small vessels, the benefit of stenting remains questionable. METHODS AND RESULTS: A total of 381 symptomatic patients with de novo focal lesion located on a small coronary segment vessel (<3 mm) were randomly assigned to either stent implantation (192 patients; 197 lesions) or standard balloon angioplasty (189 patients; 198 lesions). The primary end point was the angiographic restenosis rate at 6 months, as determined by quantitative coronary angiography. On intention-to-treat analysis, angiographic success rate and major adverse cardiac events were comparable: 97.9% and 4.6% versus 93.9% and 5.8% in the stent group and the balloon group, respectively. After the procedure, a larger acute gain was achieved with stent placement (1.35+/-0.45 versus 0.94+/-0.47 mm, P=0.0001), resulting in a larger minimal lumen diameter (2.06+/-0.42 versus 1.70+/-0.46 mm, P=0.0001). At follow-up (obtained in 91% of patients), angiographic restenosis rate was 21% in the stent group versus 47% in the balloon group (P=0.0001), a risk reduction of 55%. Repeat target lesion revascularization was less frequent in the stent group (13% versus 25%, P=0.0006). CONCLUSIONS: Elective stent placement in small coronary arteries with focal de novo lesions is safe and associated with a marked reduction in restenosis rate and subsequent target lesion revascularization rate at 6 months.

Angioplasty, Balloon, Coronary↗

PubMed2001

Clinical and angiographic performance of a new-generation modular stent design for treatment of de novo coronary lesions.

The objectives of the Race Car study were to assess the safety and efficacy of the Medtronic AVE S670 stent, a new-generation stent with a modular design consisting of interconnected sinusoidal rings allowing improved flexibility with good conformability and scaffolding. A total of 285 stents were implanted in 267 patients with (un)stable angina pectoris who underwent angioplasty of a single de novo lesion in a native coronary artery with a diameter between 3.0 and 4.0 mm. Available stent lengths were 9, 12, and 15 mm. The primary endpoint was the 6-month restenosis rate. Secondary endpoints were device and procedural success and major adverse cardiac event (MACE)-free survival at 1 and 6 months. All patients received the study stents and no other stents were used (angiographic success: 100%). Eight patients experienced a MACE during hospital admission (Q-wave MI in 2, non-Q-wave MI in 4, TLR in 2). A procedural success was obtained in 97% of the patients. There were no additional events at 1 month. The clinical endpoints encountered at 6 months were Q-wave MI in 1, bypass surgery in 3, and repeat angioplasty in 25 (MACE-free survival: 86.5%). Quantitative angiographic results were the minimum lumen diameter increased from 1.05 +/- 0.32 before to 2.73 +/- 0.39 mm after stent implantation. At follow-up, the loss in diameter was 0.74 +/- 0.50 mm. The loss index was 0.45 +/- 0.31 and restenosis rate was 13.4%. This study has demonstrated that the S670 stent in patients with (un)stable angina pectoris requiring intervention of a single lesion has a low acute and 6-month major event rate and a low angiographic restenosis rate.

Aged↗

PubMed2001

Properties and substrate of slow pathway exposed with a compact node targeted fast pathway ablation in rabbit atrioventricular node.

INTRODUCTION: The properties and substrates of slow and fast AV nodal pathway remain unclear. This applies particularly to the slow pathway (SP), which is largely concealed by fast pathway (FP) conduction. We designed a new FP ablation approach that exposes the SP over the entire cycle length range and allows for its independent characterization and ablation. METHODS AND RESULTS: Premature stimulation was performed before and after FP ablation with 5.4 +/- 1.9 lesions (300-microm diameter each; overall lesion size 1.4 +/- 0.5 mm) targeting the junction between perinodal and compact node tissues in seven rabbit heart preparations. The resulting SP recovery curve and control curve had the same maximum nodal conduction time (165 +/- 22 msec vs 164 +/- 24 msec; P = NS) and effective refractory period (101 +/- 10 msec vs 100 +/- 9 msec; P = NS). The two curves covered the same cycle length range. However, the SP curve was shifted up with respect to control one at intermediate and long cycle lengths and thus showed a longer minimum nodal conduction time (81 +/- 15 msec vs 66 +/- 10 msec; P < 0.01) and functional refractory period (180 +/- 11 msec vs 170 +/- 12 msec; P < 0.05). The SP curve was continuous and closely fitted by a single exponential function. Small local lesions (2 +/- 1) applied to the posterior nodal extension resulted in third-degree nodal block in all preparations. CONCLUSION: The posterior nodal extension can sustain effective atrial-His conduction at all cycle lengths and account for both the manifest and concealed portion of SP. Slow and FP conduction primarily arise from the posterior extension and compact node, respectively.

Animals↗

PubMed2000

A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. STENTIM-2 Investigators.

OBJECTIVES: In a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI). BACKGROUND: Primary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate. METHODS: A total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis. RESULTS: Angiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (> or = 50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1). CONCLUSIONS: In the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.

Angioplasty, Balloon↗

PubMed1999

Role of the compact node and its posterior extension in normal atrioventricular nodal conduction, refractory, and dual pathway properties.

INTRODUCTION: The functional origin of AV nodal conduction, refractory, and dual pathway properties remains debated. The hypothesis that normal conduction and refractory properties of the compact node and its posterior nodal extension (PNE) play a critical role in the slow and the fast pathway, respectively, is tested with ablation lesions targeting these structures. METHODS AND RESULTS: A premature atrial stimulation protocol was performed before and after PNE ablation in six isolated rabbit heart preparations. Discrete (approximately 300 microm) histologically controlled PNE lesions amputated the AV nodal recovery curve from its left steep portion reflecting slow pathway conduction and prevented reentry without affecting the right smooth fast pathway portion of the curve. The ablation shortened A2H2max from 159 +/- 16 ms to 123 +/- 11 msec (P < 0.01) and prolonged the effective refractory period from 104 +/- 6 msec to 119 +/- 11 msec (P < 0.01) without affecting A2H2min (55 +/- 9 msec vs 55 +/- 8 msec; P = NS) and functional refractory period (174 +/- 7 msec vs 175 +/- 6 msec; P = NS). These results did not vary with the input reference used. In six other preparations, lesions applied to the compact node after PNE ablation shifted the fast pathway portion of the recovery curve to longer conduction times and prolonged the functional refractory period, suggesting a compact node involvement in the fast pathway. CONCLUSION: The normal AV nodal conduction and refractory properties reflect the net result of the interaction between a slow and a fast pathway, which primarily arise from the asymmetric properties of the PNE and compact node, respectively.

Animals↗

PubMed1999

Characteristics, circuit, mechanism, and ablation of reentry in the rabbit atrioventricular node.

INTRODUCTION: The circuitry underlying AV nodal reentry remains debated. We developed a model of AV nodal reentry and assessed the role of nodal inputs, compact node, and its posterior nodal extension (PNE) in this phenomenon. METHODS AND RESULTS: A fine scanning of short coupling interval range with an atrial premature beat consistently initiated slow-fast AV nodal reentrant beats that occurred 37+/-31 msec (mean+/-SD) after His-bundle activation in 11 of 16 consecutive rabbit heart preparations. The repeated testing (>40 times) of a chosen coupling interval within reentry window (6+/-9 msec, n = 11) yielded reentrant intervals that varied by 2+/-1 msec (mean SD for 40 beats+/-SD, n = 11). The breakthrough point of reentrant activation, as assessed from four perinodal sites, varied in different preparations from diffuse (4) to anterior (1), medial (3), or posterior (3); mean reentrant interval did not differ between perinodal sites. Antegrade perinodal activation pattern did not differ at reentrant versus nonreentrant coupling intervals and thus was not a primary determinant of reentry. A PNE ablation (n = 4) interrupted the slow pathway conduction and prevented reentry without affecting antegrade perinodal activation or fast pathway conduction. CONCLUSION: A reproducible model of AV nodal reentrant beats was developed and used to study underlying circuitry. The AV nodal reentry involves unaltered antegrade perinodal activation, slow PNE conduction and retrograde broad invasion of perinodal tissues starting at a preparation-dependent breakthrough point. A PNE ablation abolishes the reentry.

Animals↗

PubMed1998

Anatomic and functional characteristics of a slow posterior AV nodal pathway: role in dual-pathway physiology and reentry.

BACKGROUND: The AV node is frequently the site of reentrant rhythms. These rhythms arise from a slow and a fast pathway for which the anatomic and functional substratum remain debated. This study proposes a new explanation for dual-pathway physiology in which the posterior nodal extension (PNE) provides the substratum for the slow pathway. METHODS AND RESULTS: The anatomic and functional properties of the PNE were studied in 14 isolated rabbit heart preparations. A PNE was found in all studied preparations. It appeared as an elongated bundle of specialized tissues lying along the lower side of Koch's triangle between the coronary sinus ostium and compact node. No well-defined boundary separated the PNE, compact node, and lower nodal cell bundle. The electric properties of the PNE were characterized with a premature protocol and surface potential recordings from histologically controlled locations. The PNE showed cycle-length-dependent posteroanterior slow activation with a shorter refractory period (minimum local cycle length) than that of the compact node. During early premature beats resulting in block in transitional tissues, the markedly delayed PNE activation could propagate to maintain or resume nodal conduction and initiate reentrant beats. A shift to PNE conduction resulted in different patterns of discontinuity on conduction curves. Transmembrane action potentials recorded from PNE cells in 6 other preparations confirmed the slow nature of PNE potentials. CONCLUSIONS: The PNE is a normal anatomic feature of the rabbit AV node. It constitutes a cycle-length-dependent slow pathway with a shorter refractory period than that of the compact node. Propagated PNE activation can account for a discontinuity in conduction curves, markedly delayed AV nodal responses, and reentry. Finally, the PNE provides a substratum for the slow pathway in dual-pathway physiology.

Action Potentials↗

PubMed1998

Use of anti-GP IIb-IIIa in acute thrombosis after intracoronary stent implantation.

Acute occlusion of coronary stents still occurs in 0.5-2% of patients. The usefulness of GP IIb-IIIa receptor inhibitors has never been evaluated in this indication. After 1,454 stent implantations, acute occlusion occurred in 16 patients. Direct percutaneous transluminal coronary angioplasty (PTCA) was immediately performed. In eight patients, no recurrent thrombosis occurred during the 15 min following PTCA, and abciximab infusion was started after this period. In six patients, immediate recurrent thrombosis occurred in the stent. In these cases, an intravenous bolus of abciximab followed by a new inflation at low pressure was performed. Fifteen min after the bolus, stable TIMI 3 flow was restored in all six cases, and no thrombus or haziness remained. In two patients, a TIMI 0 flow persisted despite PTCA and the use of a bolus of abciximab. No recurrent ischemic symptoms were observed before hospital discharge. Abciximab in combination with balloon angioplasty can be used safely to control acute thrombosis after stent deployment.

Abciximab↗

PubMed1995

Cholesterol content of circulating immune complexes in patients with coronary stenosis and subjects without evidence of atherosclerosis.

The biological variation factors for cholesterol in circulating immune complexes (CIC-cholesterol) were studied in 941 unselected supposedly healthy volunteers, ages 4 to 78 years. We found a complex effect of age, including the existence of two peaks of CIC-cholesterol, one in males between 11 and 14 years and in females between 11 and 30 years, and in both sexes another peak between 41 and 60 years, and in both sexes a decrease between 31 and 40 years. By use of multiple regression analysis and after adjustment for age, CIC-cholesterol was positively related to plasma cholesterol concentration and leukocyte count, values being lower in females than in males and among subjects taking anti-inflammatory drugs. In addition, CIC-cholesterol was measured in 76 coronary angiography patients and in 100 supposedly healthy controls, ages 30 to 77 years. We noticed a significant increase (P < or = 0.05) of CIC-cholesterol when patients were affected by coronary stenosis between 20% and 50% (71.8 +/- 52.5 mumol/L vs 46.2 +/- 45.9 mumol/L in controls), but this was less pronounced in those with > 50% of obstruction (58.9 +/- 54.3 mumol/L); however, serum total cholesterol was not modified or even surprisingly slightly decreased in the coronary angiography individuals. Nevertheless, an important overlap of values in controls and patients makes questionable the usefulness of this variable in clinical practice.

Adolescent↗

PubMed1989

[Survival in primary dilated cardiomyopathy as a function of tobacco smoking. A retrospective study].

In order to determine the influence of tobacco smoking on the course and long-term prognosis of idiopathic dilated cardiomyopathy, we conducted a retrospective study of 111 patients (95 men and 16 women, mean age 45.5 +/- 8.1 years) who had undergone cardiac catheterization between January 1970 and December 1979 and had been followed up for 6 to 16 years. The criteria of inclusion was diffuse hypokinesia of the left ventricle with an ejection fraction of 50 per cent or less, normal coronary arteriography and cardiomyopathy of unknown origin. The overall mortality rates at 1, 5 and 10 years were 10, 50 and 66 per cent respectively, and the main predictive factor was the left ventricular ejection fraction. Forty-six per cent of these patients were smokers, 19 per cent were non-smokers and 35 per cent had undetermined smoking habits. A univariate analysis showed a favourable predictive effect of smoking on survival (P less than 0.01), and this was confirmed by the statistical hypothesis of maximum bias for patients with undetermined smoking habits. On multivariate analysis, this predictive effect was superseded by the left ventricular ejection fraction, but after stratification of the sample according to the mean value of ejection fraction (30 per cent), the predictive value of smoking reappeared clearly in the group with a less than 30 per cent ejection fraction (P less than 0.003).

Adult↗

PubMed1988

Dilated cardiomyopathy: long-term follow-up and predictors of survival.

To determine long-term survival and the prognostic factors of dilated cardiomyopathy, we retrospectively studied a consecutive series of 111 patients (95 men, 16 women, mean age: 45.5 +/- 8.1 years) undergoing cardiac catheterization and diagnostic coronary angiography from January 1970 to December 1979. The inclusion criteria were: normal coronary angiography, diffuse hypokinesia of the left ventricle and left ventricular ejection fraction less than 50%. Base-line clinical data were collected from the hospital records and follow-up data were obtained from the general practitioners and cardiologists. A questionnaire was sent to all living patients. The length of follow-up ranged from 6 to 16 years. Six patients (5%) were lost to follow-up. At the time of catheterization, a majority of the patients had dyspnea and were in New York Heart Association (NYHA) classes II (41%) and III (31%). Clinical history revealed an excessive alcohol consumption in 56% of the patients. During follow-up, 66 patients (63%) died (heart failure: 37%; sudden death: 19%; non-cardiac death: 15%; unknown cause: 27%). Actuarial survival was 90, 50, and 33% at 1, 5, and 10 years, respectively. Univariate analysis revealed that 10-year mortality was related to: left ventricular ejection fraction less than 30%; left ventricular end-diastolic pressure greater than 10 mm Hg; cardiothoracic ratio greater than 54%; episodes of heart failure; left ventricular end-diastolic volume greater than 200 ml/m2, dyspnea of NYHA class III or IV; absence of smoking; absence of moderate systemic hypertension; electrocardiographic evidence of left ventricular hypertrophy and mean systemic arterial pressure greater than 95 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

[Coronary angioplasty in the elderly patient. Immediate results and mid-term outcome].

Between April 1980 and July 1986, 50 patients over 65 (32 men and 18 women; mean age: 72 years) were treated by transluminal coronary angioplasty. Before the dilatation, 58 p. cent of the patients presented a severe angor (class III or IV) and 44 p. cent were multi-truncular. The dilatation was successful in 39 patients (78%) and 13 patients developed a recurrent stenosis successfully treated in 9 instances by re-dilatation. Among the complications, there were 2 deaths (4%), 3 infarctions (6%) and 3 emergency coronary bypass operations (6%). With a mean 28 months follow-up, the overall survival is 92 p. cent. After a successful dilatation, 49 p. cent of the patients are completely asymptomatic and the subsequent cardiological hospitalizations are rare (11%). These results show that coronary dilatation represents an interesting therapeutic option in elderly coronary patients.

Aged↗

PubMed1988

[Semiquantitative evaluation of mitral insufficiency by pulsed Doppler technic. Value of a simple index of left auricular cartography (apropos of a series of 63 patients)].

The authors advocate a semiquantitative evaluation of mitral regurgitation (MR), based on the extent of the left intra-atrial systolic jet. Their study was performed in a series of 63 consecutive patients explored by: (1) catheterization with left ventriculography on two planes for either ischaemic heart disease (24 cases) or cardiac valve disease (39 cases including 2 with mitral valve prosthesis), and (2) pulsed Doppler ultrasound combined with two-dimensional echocardiography for evaluation of MR carried out 24 or 48 hours prior to catheterization. Five grades of MR (0 to IV) were determined by ventriculography according to the time and degree of left atrial opacification. Similarly, five grades of MR (0 to IV) were determined by Doppler ultrasound, considering only the maximum distance from the mitral annulus plane. This distance was evaluated on at least 3 projections: apical for the 4 and 2 cavities, parasternal for the greater axis. The Doppler method correlated fairly well with the angiography, whether or not grade 0 was included (r = 0.87 and r = 0.72 respectively). However, some major MR may be underestimated; thus, out of 13 RM of angiographic grade III or IV, three (23 p. 100) were graded II by the Doppler technique. Conversely, some minute or moderate MR may be overestimated: out of 33 MR of angiographic grade I or II, four (12 p. 100) were graded III or IV by the Doppler technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

[Prognosis of spontaneous occlusions in tight coronary stenosis].

Eighteen out of 408 patients assigned to coronary angioplasty rapidly developed complete obstruction of the vessel to be dilated. The results of a retrospective study of clinical, biochemical, angiographic and/or angio-scintigraphic events in these 18 patients are reported. The interval between the two coronary arteriographies was 67 +/- 66 days. Angina was initially unstable in 9 patients and stable in 6; 3 patients were asymptomatic. Coronary lesions followed the usual distribution pattern: the left anterior descending artery was involved in 11 cases, the circumflex artery in 4 cases and the right coronary artery in 3 cases. Overall, the degree of stenosis was high (86 +/- 7%); Following obstruction the course of the disease was favourable in 11 patients (61%), with complete remission of all symptoms in 5. Six patients remained with unstable angina. Apart from one case of sudden death, none of the patients developed myocardial infarction, as shown by the absence of significant biochemical, electrical and angiographic changes. The importance of pre-existing or newly developed collateral circulation as a good prognosis factor is highlighted.

Adult↗

PubMed1987

Placebo-controlled study of oral enoximone in congestive heart failure with initial and final intravenous hemodynamic evaluation.

Seventeen patients with stable congestive heart failure (class II and III New York Heart Association) received intravenous and oral enoximone in a 2-part study. Hemodynamic data were first obtained after intravenous administration of 0.75 mg/kg of enoximone; data were again obtained after 12 weeks of therapy with either oral enoximone (150 mg 3 times daily) or placebo. The efficacy and safety of oral enoximone were also studied in a 12-week, double-blind randomized format. In the intravenous study, enoximone was delivered over 5 minutes and hemodynamic data were measured for up to 12 hours after. Cardiac index increased 2.76 +/- 0.63 to 3.42 +/- 0.72 liters/min/m2), pulmonary wedge pressure decreased (19.5 +/- 8.8 to 14.6 +/- 8.0 mm Hg) as did mean arterial blood pressure (101 +/- 14.8 to 85 +/- 13.7 mm Hg) and systemic vascular resistance (1,880 +/- 573 to 1,254 +/- 383 dynes s cm-5). Heart rate increased slightly (82 +/- 17 to 86 +/- 14 beats/min). All these changes were maximal 1 to 2 hours after infusion and lasted 8 hours at least. Patients were then randomized double-blind to oral treatment. Baseline values showed that the 7 patients who received placebo had more severe CHF. Therefore, comparison might be biased. Patient overall assessment showed a continuous benefit in both groups. Ejection fraction improved from 30.1 +/- 6.8% to 33.9 +/- 9.9% in the enoximone group while it remained unchanged with placebo (23.4 +/- 6.5% to 23.4 +/- 1.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1987

Electrophysiologic effects and pharmacokinetics of intravenous penticainide (CM 7857).

Penticainide is a new class I antiarrhythmic agent. Its electrophysiological effects and pharmacokinetic properties were studied in 28 patients undergoing endocavitary exploration for paroxysmal supraventricular tachycardia (10 cases), WPW syndrome involving an accessory pathway (5 cases), and unexplained dizziness (13 cases). Increasing doses of penticainide were infused in the first 18 patients (0.12 up to 3.5 mg kg-1). The next ten patients received 4 mg kg-1 over a 30 minute period. Penticainide shortened the sinus cycle length and increased the transnodal conduction time. The ventricular conduction time tended to increase. Atrial functional refractory period increased when atrioventricular nodal and ventricular refractory periods remained unchanged. In patients with previous supraventricular tachycardias all triggered arrhythmias were prevented with dosages higher than 2 mg kg-1 and related blood levels higher than 3 mg l-1. A dose-dependency of plasma and renal clearance was documented. Average Cmax values after 4 mg kg-1 was 7.37 +/- 1.28 mg l-1. No adverse events occurred during the trial and penticainide proved to be well tolerated.

Adult↗

PubMed1987

[Outcome of 195 patients with Wolff-Parkinson-White syndrome].

Between 1974 and 1984, 207 patients with Wolff-Parkinson-White syndrome (WPW) were admitted to our hospital department; 195 of them were followed up for periods ranging from 1 to 12 years (6 years in children, 3 years and 9 months in adults on average); 160 had undergone electrophysiological exploration. Fifty-seven patients were less than 16 years old: 7 died, including 6 with associated congenital heart disease; an asymptomatic 12-year old girl died suddenly while taking part in a sporting event. The signs of WPW disappeared in 5 out of 10 children under 1 year of age. One hundred and thirty-eight patients were older than 15: 15 of them died, but only 3 deaths were related to WPW: one was consecutive to surgery for WPW and one to fulguration; the third patient died of WPW tachyarrhythmia; the refractory period of his Kent's bundle was short, but his compliance with treatment was irregular. We found no correlation between changes in functional symptoms and Kent's bundle refractory period values; paradoxically, the frequency of attacks and resistance to treatment was higher in cases with long refractory period. On the whole, this series confirms that WPW usually is a benign disease. However, the risk of sudden death, of which it offers an example, indicates that all patients with WPW should be evaluated with at least an exercise test and, depending on its results or on the socio-professional context, an electrophysiological exploration.

Adolescent↗

PubMed1986

[Isotopic exercise tests and selection of cases of inferior infarction requiring coronarography].

Exercise tests involving isotopes were evaluated in 38 subjects presenting inferior myocardial necrosis. Cardiographic data were used to calculate sensitivity and specificity of the method in detection of subjects requiring surgical treatment. Sensitivity was 90% and specificity 62% when three criteria were employed: ECG of positive exertion, reversible diminished accumulation of thallium 201 outside the necrotic site or decrease in the fraction of ejection force. Examination of the fraction of ejection force improved the results of myocardial scanning using thallium and increased detection of subjects requiring surgery from 61% to 90%.

Adult↗