Effect of exercise training on postexercise oxygen uptake kinetics in patients with reduced ventricular function.

BACKGROUND: The time required for oxygen uptake (O(2)) to return to baseline level (recovery kinetics) is prolonged in patients with reduced ventricular function, and the degree to which it is prolonged is related to the severity of heart failure, markers of abnormal ventilation, and prognosis. In the present study, we sought to determine the effect of exercise training on O(2) recovery kinetics in patients with reduced ventricular function. METHODS: Twenty-four male patients with reduced ventricular function after a myocardial infarction were randomized to either a 2-month high-intensity residential exercise training program or to a control group. O(2) kinetics in recovery from maximal exercise were calculated before and after the study period and expressed as the slope of a single exponential relation between O(2) and time during the first 3 min of recovery. RESULTS: Peak O(2) increased significantly in the exercise group (19.4 +/- 3.0 mL/kg/min vs 25.1 +/- 4.7 mL/kg/min, p < 0.05), whereas no change was observed in control subjects. The O(2) half-time in recovery was reduced slightly after the study period in both groups (108.7 +/- 33.1 to 102.1 +/- 50.5 s in the exercise group and 122.3 +/- 68.7 to 107.5 +/- 36.0 s in the control group); neither the change within or between groups was significant. The degree to which O(2) was prolonged in recovery was inversely related to measures of exercise capacity (peak O(2), watts achieved, and exercise time; r = - 0.48 to - 0.57; p < 0.01) and directly related to the peak ventilatory equivalents for oxygen (r = 0.59, p < 0.01) and carbon dioxide (r = 0.57, p < 0.01). CONCLUSION: Two months of high-intensity training did not result in a faster recovery of O(2) in patients with reduced ventricular function. This suggests that adaptations to exercise training manifest themselves only during, but not in, recovery from exercise.

Long-term treatment of patients affected by systemic sclerosis with cyclosporin A.

The aims of the present study were: 1) to verify the tolerability of long-term, low-dose treatment of patients affected by systemic sclerosis with cyclosporin A; 2) to analyze the clinical outcome of treated patients in relationship to skin, esophageal, lung, kidney and microvascular organ involvement. Nine patients affected by diffuse systemic sclerosis were treated for periods ranging from 3 to 5 years with cyclosporin A at a dosage of 2.5 mg/kg/day. Cyclosporin A treatment was variably associated or not with treatments for Raynaud's phenomenon (pentoxiphylline, defibrotide, low-dose heparin, prostacyclin analogues) in relationship to the needs of single patients. We report on patient clinical evaluations performed every year and including plicometry, esophageal pH-manometry, pulmonary spirometry, renal duplex Doppler sonography, echocardiography as well as nailfold videocapillaroscopy. The results of single tests were converted into scores. The existence of statistically significant differences between baseline mean scores and mean scores after 1, 2 and 3 years of therapy was analyzed. All patients tolerated cyclosporin A well, and no definitive withdrawals from the study were observed. Hypertricosis appeared in 3 patients, and 1 patient interrupted treatment for 6 months because of the onset of pneumonitis. No alterations of blood pressure and renal functionality were detected. Statistically significant reduction of all analyzed mean scores was observed after 2 and/or 3 years of cyclosporin A treatment with respect to baseline. The overall results suggest an encouraging clinical effect for low-dose, long-term cyclosporin A treatment in systemic sclerosis. Satisfactory tolerability and clinical improvement were observed in all the patients consecutively treated for at least 3 years.

Cyclosporin A and iloprost treatment of systemic sclerosis: clinical results and interleukin-6 serum changes after 12 months of therapy.

OBJECTIVES: The main aim was to analyse the long-term therapeutic effects on systemic sclerosis (SSc) patients of treatment with either (i) iloprost alone or (ii) low-dose oral cyclosporin A (CyA) associated with iloprost. A secondary aim was to analyse interleukin-6 (IL-6) serum levels in SSc patients before and after 1 yr of treatment. METHODS: A clinical trial was performed in which 20 consecutive SSc patients were alternately randomized into two homogeneous groups receiving either monthly i.v. iloprost (1 ng/kg/min in 6 h i.v. infusion, for 5 consecutive days, 1 week per month) (Group I) or low-dose CyA (2.5 mg/kg/day) associated with iloprost administration (Group II). IL-6 concentrations were evaluated by ELISA in the sera of each patient before and after 1 yr of therapy and in 20 healthy subjects. RESULTS: After 1 yr of therapy, a significant improvement of skin (P=0.008), microvascular (P=0.004) and oesophageal (P=0.05) morphological and functional parameters was observed only in Group II patients. Furthermore, after 1 yr of treatment, a significant reduction (P=0.007) of IL-6 serum concentration was observed only in Group II patients. CONCLUSIONS: Collectively, our data suggest that the combination of low-dose CyA with iloprost administration may be of clinical utility in SSc and that a mechanism of action of CyA in SSc may include the decrease in IL-6 production.

Effect of betaxolol on the hemodynamic, gas exchange, and cardiac output response to exercise in chronic atrial fibrillation.

BACKGROUND: beta-blockade controls the ventricular response to exercise in chronic atrial fibrillation (AF), but the effects of beta-blockers on exercise capacity in AF have been debated. METHODS: Twelve men with AF (65+/-8 years) participated in a randomized, double-blind, placebo-controlled study of betaxolol (20 mg daily). Patients underwent maximal exercise testing with ventilatory gas exchange analysis, and a separate, submaximal test (50% of maximum) during which cardiac output was measured by a CO2 rebreathing technique. RESULTS: After betaxolol therapy, heart rate was reduced both at rest (92+/-27 vs 62+/-12 beats/min; p < 0.001) and at peak exercise (173+/-22 vs 116+/-24 beats/min; p < 0.001). Maximal oxygen uptake (VO2) was reduced by 19% after betaxolol (21.8+/-5.3 with placebo vs 17.6+/-5.1 mL/kg/min with betaxolol; p < 0.05), with similar reductions observed for maximal exercise time, minute ventilation, and CO2 production. VO2 was reduced by a similar extent (19%) at the ventilatory threshold. Submaximal cardiac output was reduced by 15% during betaxolol therapy (12.9+/-2.3 vs 10.9+/-1.3 L/min; p < 0.05), and stroke volume was higher (88.0+/-21 vs 105.6+/-19 mL/beat; p < 0.05). CONCLUSION: Betaxolol therapy in patients with AF effectively controlled the ventricular rate at rest and during exercise, but also caused considerable reductions in maximal VO2 and cardiac output during exercise. The observed increase in stroke volume could not adequately compensate for reduced heart rate to maintain VO2 during exercise.

Screening for abdominal aortic aneurysms and associated risk factors in a general population.

OBJECTIVES: To evaluate the prevalence of abdominal aortic aneurysms (AAA) in a general population and to compare the results with those of similar studies in other countries. DESIGN: Ultrasound screening study and collection of clinical and biochemical data. SETTING: An urban Health Service District in Genoa, Italy. MATERIALS: A general population, aged 65-75 years, invited by personal letter between 1991-1994. RESULTS: 1601 subjects (741 males and 860 females) out of 2734 invited (58.5%) were evaluated. According to the ultrasound findings, 27 patients (1.7%) had an aortic dilatation of 26-29 mm; an AAA of 30-39 mm was found in 37 (2.3%) and an AAA > or = 40 mm in 33 (2.1%). The overall prevalence for AAA was 4.4% (8.8% in males and 0.6% in females respectively). The prevalence of smoking, alcohol consumption, coronary heart disease, chronic obstructive pulmonary disease and arterial disease were significantly higher in patients with AAA (p < 0.01). CONCLUSIONS: Ultrasound screening for AAA is a reliable and useful method and should be focused on men, regardless of concurrent disease.

Favourable results of treatment of narrowed saphenous vein grafts with Palmaz-Schatz stent implantation.

Although conventional balloon angioplasty of saphenous vein grafts can be performed with an acceptable acute success and complication rate, restenosis remains a major problem. However, this may be overcome by the implantation of Palmaz-Schatz stents. Palmaz-Schatz stent deployment was performed in our institution in 43 patients who were referred for PTCA of stenosed saphenous vein grafts. Thirty-seven were located at the mid-portion of the graft, seven at the ostium and six at the distal anastomosis. Overall, we used 59 standard length (15 mm) Palmaz-Schatz stents and 22 short (7 mm) stents. In 15 lesions (30%) multiple stents were implanted in tandem to treat diffuse disease. Angiographic success was achieved in 47 of the 50 attempted lesions (94%). Major cardiac complications occurred in three patients. Two patients had procedures complicated by the development of a Q wave myocardial infarction, one of whom underwent urgent CABG. One patient died. There was no episode of subacute thrombosis. The angiographic follow-up of 37 lesions (80% of eligible lesions) at a mean time of 5 +/- 2 months (range 1-8) showed a restenosis rate of 11% and residual post-stent diameter stenosis was associated with a significantly higher restenosis rate. However, no restenosis occurred in lesions receiving multiple stents. Clinical follow-up was performed in all patients, and at a mean of 25 months after the procedure, 64% were free from clinical events, including recurrent angina. Palmaz-Schatz stent implantation is an effective and safe procedure to treat narrowed vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

[Screening for abdominal aortic aneurysms in the general population. Preliminary results]. / Screening per gli aneurismi dell'aorta addominale nella popolazione generale. Risultati preliminari.

Between March 1991 and April 1993, 1188 subjects aged 65-75 years, out of 2734 invited, underwent abdominal ultrasound for screening of asymptomatic abdominal aortic aneurysms (AAA). For each patient the maximal anteroposterior and transverse diameters of the suprarenal and infrarenal aorta were measured. According to the literature data an AAA is defined as an aortic dilatation > 29 mm. AAA < 40 mm are followed by ultrasound every 6 months and the AAA > 39 mm are considered for surgical repair after complete clinical work-up. In addition any aortic dilatation ranging 26-29 mm is followed too, using the same criteria. The aorta was normal in 1112 patients (95.12%), an infrarenal aortic dilatation was found in 21 patients (1.79%), an AAA < 40 mm in 15 patients (1.28%) and an AAA > 39 mm in 21 patients (1.79%). The global prevalence of AAA > 29 mm was 3.07% (0.3% for the females and 6.8% for the males), similar to that reported by other authors. The statistically significant (p < 0.01) risk factors were: smoking, alcohol consumption, coronary disease and chronic lung obstruction. Hypertension and dyslipidaemia were not significant (but HDL-cholesterol and Apo-B), according to a different etiology of the aneurysms. In addition 38.5% of the patients had total cholesterol > 240 mg/dl but only 34.9% of these was under medical treatment and/or on a diet. Our preliminary data confirm the results of similar studies in other countries: screening for AAA is worthwhile on the general population and, looking to a better cost-benefit rate, it might be focused only on males.

Survival after percutaneous transluminal coronary angioplasty in patients with severe left ventricular dysfunction.

To assess the effects of coronary angioplasty in patients with severe left ventricular dysfunction, the results of procedures, performed between 1987 and 1991, in 100 patients (90 male) with left ventricular function < or = 0.35 (range, 0.20 to 0.35) and anginal symptoms were analyzed. Mean age was 62 +/- 10 years (range, 38 to 85 years). Ninety-five patients had previous myocardial infarction and 27 patients had previous coronary artery bypass grafting. Unstable angina was present in 81 percent of patients. Single-vessel disease was present in 6 patients, double vessel was present in 31 patients, and triple-vessel disease was present in 63 patients. Percutaneous transluminal coronary angioplasty (PTCA) was attempted on 164 vessels, 27 of these with chronic total occlusion. The overall angiographic success rate was 84 percent. Myocardial infarction occurred in four patients, six patients underwent urgent coronary bypass surgery, and seven patients died of cardiac causes. There was a 9 percent incidence of total in hospital mortality. Major complications were significantly more frequent in patients with triple-vessel disease. Clinical success was achieved in 75 patients, 55 of these with incomplete revascularization. Long-term follow-up (mean, 19 +/- 7 months) was available in all patients with clinical success. Thirteen patients had repeated PTCA, 8 patients had coronary surgery, and 13 patients died. In conclusion, in patients with severe left ventricular dysfunction, acute complications and late mortality rate are high. Patients with triple-vessel disease are a higher risk subset and have no long-term benefits by PTCA.

[Moxonidine vs. captopril in minor to intermediate hypertension. Double-blind study of effectiveness and tolerance]. / Moxonidin vs. Captopril bei leichter bis mittelschwerer Hypertonie. Doppelblindstudie zur Wirksamkeit und Verträglichkeit.

In a randomized double-blind study, the antihypertensive efficacy and tolerance of the imidazoline receptor agonist, moxonidine, were compared with those of the ACE inhibitor, captopril. Included in the trial were 50 ambulatory patients with mild-to-moderate hypertension, who were treated for 4 weeks with either 0.2-0.4 mg moxonidine, or 25-50 mg captopril daily. Both substances clearly reduced hypertension; no statistically significant difference was seen between the two groups. Under moxonidine, the mean blood pressure while seated decreased from 176/101 mm Hg to 155/91 mm Hg by the end of treatment; under captopril the corresponding figures were 170/99 and 150/89 mm Hg. Minor transient side effects, for the most part with a doubtful relationship to the treatment, were seen in 5 patients (20%) of the moxonidine group, and in 8 patients (32%) of the captopril group. Thus, in this study, moxonidine and captopril proved to have equivalent antihypertensive efficacy and good tolerability.

Coronary stenting for treatment of acute or threatened closure following dissection after coronary balloon angioplasty.

We studied 32 patients (age 58 +/- 9 years) who had been treated with a Palmaz-Schatz stent after significant dissection complicating percutaneous transluminal coronary angioplasty (PTCA). We attempted to cover the entire site of dissection with prosthesis. The presence of dissection after PTCA was associated with Thrombolysis in Myocardial Infarction grade 0 to 1 flow in 19 patients and grade 2 flow in 13. The stented arteries were: left anterior descending artery in 19 patients, right coronary artery in seven, and left circumflex artery in five. A single stent was implanted in 11 and multiple stents in 21 patients. Angiographic success was achieved in 30 patients (94%). Two patients (6%) had urgent coronary artery bypass graft surgery, two (6%) had a myocardial infarction, and one (3%) patient died. Subacute occlusion occurred in one patient (3%). Angiographic restenosis was found in three of nine patients (33%) with a single stent and 11 of 17 (65%) with multiple stents. Clinical follow-up at 11 +/- 3 months showed the necessity of coronary artery bypass graft surgery in two patients and repeat PTCA in nine (31%). We conclude that coronary stenting is an effective treatment for significant coronary dissection after PTCA with an acceptable incidence of major cardiac events at follow-up.

Norepinephrine-induced plasma dopamine decrease in man: pharmacological evidence of the involvement of alpha 2-adrenoceptors.

OBJECTIVE: The purposes of this study were: (1) to test whether intravenous infusion of norepinephrine can affect plasma dopamine levels; and (2) to explore to what extent dopamine-2 or alpha 2-receptors play a role in this response. DESIGN: Norepinephrine infusion in man was performed to test whether the increase in norepinephrine during sympathetic stimulation can affect dopamine release. Specific antagonists of presynaptic dopamine-2 and alpha 2-receptors were administered to test the receptor(s) involved in this possible regulatory phenomenon. METHODS: Plasma catecholamine levels were investigated in seven normal subjects before and after administration of domperidone (dopamine-2 antagonist), yohimbine (alpha 2-antagonist) and norepinephrine. RESULTS: Both oral domperidone and yohimbine induced a significant increase in both plasma norepinephrine and plasma dopamine. Norepinephrine infusion induced a significant decrease in plasma dopamine. Pretreatment with domperidone only partially counteracted this inhibitory effect of norepinephrine infusion, whereas yohimbine fully counteracted it. CONCLUSIONS: Our data show that norepinephrine may act as a hormone at plasma concentrations as low as 450 pg/ml. The norepinephrine-induced plasma dopamine decrease seems to be alpha 2-adrenoceptor-mediated. This norepinephrine effect may be involved in the physiologic decrease in plasma dopamine that we demonstrated in the upright position in normal subjects.

Coronary angioplasty of chronic occlusions: factors predictive of procedural success.

In a retrospective study of 365 chronic total occlusions that were submitted for angioplasty, we studied the influence of 27 clinical, morphologic, and procedural variables as possible predictors of successful outcomes. Success rate was shown to be significantly influenced by the following variables: operator experience (41% in early patients, first 6 months; 73% in late patients, last 6 months of entire series; p less than 0.001), duration of occlusion (less than or equal to 1 month, 89%; 1 to 3 months 87%; greater than or equal to 3 months 45%; unknown 60%; p less than 0.001), morphology of occlusion (tapered, 83%; abrupt, 51%), length of occlusion (less than or equal to 15 mm, 71%; greater than 15 mm, 60%; p less than 0.001), and bridging collaterals (present, 29%; absent, 67%; p less than 0.001). None of the other clinical, angiographic, or procedural variables correlated with the success rate of coronary angioplasty. The calculated probability for an experienced operator (greater than 100 occlusions attempted) to successfully open an occlusion with favorable morphology (less than or equal to 1 month old, short, tapered, without bridging collaterals) is 99%. An attempt by the same operator to open an occlusion with unfavorable structure (greater than or equal to 3 months old, long, untapered) has only 47% probability of success. The probability increases to 84% when the occlusion is tapered. We concluded that in addition to the duration and the length of occlusion, tapered morphology, bridging collaterals, and operator experience can predict successful angioplasty in chronic total coronary occlusion.

Results of coronary angioplasty in patients aged 75 years and older.

We studied a group of 47 patients greater than or equal to 75 years old. The mean age was 77 +/- 1.5 years and there were 28 (60 percent) male patients. Multivessel disease was present in 72 percent. Angioplasty was successful in 93 percent of 90 stenoses and in 30 percent of ten total occlusions. Single vessel angioplasty was done in 53 percent of patients, double vessel in 28 percent and triple vessel in 19 percent. Incomplete or absent revascularization was present in 47 percent and 9 percent, respectively. Primary clinical success was accomplished in all patients with single vessel disease; in 85 percent of patients with double vessel disease, and in only 52 percent of patients with triple vessel disease. Complications were highest in patients with triple vessel disease: 14 percent mortality and 5 percent emergency CABG. The follow-up at one year showed 91 percent survival. The PTCA is a valid alternative method of revascularization in elderly patients with single and double vessel disease. The results in triple vessel disease are less encouraging.

Percutaneous transluminal coronary angioplasty in patients aged 70 years and older: immediate and long-term results.

We analyzed all coronary angioplasty procedures performed in patients aged greater than 70 yr since 1987. There were a total of 92 patients with a mean age of 74 +/- 4 yr (range 70-82). The clinical diagnosis was unstable angina in 79%. Single-vessel disease was present in 41%, double-vessel in 29% and triple-vessel in 30% of patients. A left ventricular ejection fraction of less than 40% was present in 18 patients. Angioplasty was attempted on one vessel in 52 patients (56%), on two vessels in 29 patients (32%) and in three vessels in 10 patients (11%). Angiographic success was achieved in 96% of stenoses and in 53% of chronic total occlusions attempted. Complete revascularization was achieved in 56% of patients. Complications included three patients (3.2%) who underwent emergency coronary artery bypass grafting, 1 patient (1.1%) who sustained a myocardial infarction and 5 patients (5.4%) who died. During hospitalization, which averaged 3 +/- 2 days, 1 patients sustained reversible renal failure and 5 patients required blood transfusion for a large groin hematoma. Clinical success at discharge was 83%. At a mean follow-up of 13 months (range 3-45 months), symptomatic improvement was observed in 59 of the 76 patients who had achieved clinical success, with 42 of these patients (55%) being asymptomatic. The following clinical events occurred: myocardial infarction in 1 patient, new percutaneous transluminal coronary angioplasty in 9 and 3 patients died of cardiac reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

[Angioplasty in total occlusion of the coronary arteries: the importance of the angiographic variables]. / L'angioplastica delle arterie coronariche con occlusione totale: importanza delle variabili angiografiche.

Total coronary occlusions can be treated by coronary angioplasty with a lower success rate when compared to the angioplasty success rate of stenoses. To evaluate factors associated with successful re-opening of total coronary occlusion we evaluated 128 occlusions attempted in 120 patients. We analyzed clinical and angiographic variables. Successful re-opening was obtained in 65% of total occlusions attempted; 1 patient (0.8%) had to undergo emergency coronary artery bypass surgery. Only the morphological characteristics of the occlusions were predictive of success. When total occlusions had a tapered morphology, success was achieved in 87% of the attempts versus 50% of success without tapered morphology (p < 0.001). The success, when the occlusion was associated with the presence of bridging collaterals, was very low (present: 30% success; absent: 71% success, p < 0.005). Success for occlusions longer than 1.5 cm was lower when compared to shorter occlusions (61% vs 78%; p < 0.005). The type of occlusion (absolute, functional), the presence of a branch originating at the level of the occlusion, the duration of the occlusion, the artery and its segment were not predictive of success. Multivariate analysis showed that tapered morphology was the only variable associated with successful re-opening of a total occlusion (87% probability of success when present). We conclude that it is possible to re-open a total coronary occlusion with low complication rate and high primary success rate when careful care is applied with particular attention paid to the morphology of the occlusion.

[Coronary angioplasty in patients with compromised left ventricular function]. / Angioplastica coronarica in pazienti con funzione ventricolare sinistra compromessa.

One thousand one hundred and thirty-two percutaneous transluminal coronary angioplasties have been performed at Centro Cuore Columbus in Milan between January 1987 and September 1989. The whole population was divided into two groups: Group A (90 patients with ejection fraction less than or equal to 0.40); Group B (678 patients with ejection fraction greater than 0.40. Mean ejection fraction in Group A (0.35) was significantly lower (p less than 0.0001) than in Group B (0.56). In each group three subsets were identified: subgroup 1: total obstruction of two major epicardial vessels plus severe stenosis of the patent one; subgroup 2: total obstruction of one vessel plus severe stenosis on a different remote one; subgroup 3: all patent vessels with one or more severe stenoses on one or all. We attempted percutaneous transluminal coronary angioplasties on 923 stenosed and 161 totally obstructed vessels, with a primary success of 95 and 56% respectively. We experienced 36 major complications (7 deaths, 10 acute myocardial infarctions, 19 emergency aortocoronary bypasses in 21 patients (2.7% of the whole population). Subgroup A1 (7 patients with ejection fraction less than or equal to 0.40 and attempted percutaneous transluminal coronary angioplasties on the sole patent vessel) showed the lowest success rate (44%) and the highest complication rate: 3 deaths (42.8%); 1 acute myocardial infarction (14.2%); 3 emergency aorto-coronary by-pass (42.8%). The 83 patients in group A2 and A3, with reduced ejection fraction, did not have significantly higher complication rate than all group B patients, with normal ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac fluoroscopy for the diagnosis of coronary artery disease: a meta analytic review.

To evaluate variability in the reported accuracy of fluoroscopically detected coronary calcific deposits for predicting angiographic coronary disease, we applied meta analysis to 13 consecutively published reports comparing the results of cardiac fluoroscopy with coronary angiography. Population characteristics and technical and methodologic factors were analyzed. Sensitivity and specificity for predicting serious coronary disease compare quite well with those from the literature on the exercise ECG and the exercise thallium scintigram. Sensitivity increases and specificity decreases more significantly with patient age, and sensitivity is paradoxically lower in laboratories testing patients with more severe disease, as well as when 70% rather than 50% diameter narrowing is used to define angiographic disease. Work-up and test review bias were also significantly related to reported accuracy.

Plasma dopamine response to sympathetic activation in man: a biphasic pattern.

We studied the plasma catecholamine response to standing and bicycle ergometric tests in 16 normal male subjects. During the standing test (performed in 10 subjects), we observed an early increase in plasma dopamine together with the fast increase in norepinephrine values; in the second half of this test (i.e. from 5 to 10 min of standing), we observed an increase in plasma dopamine levels. During the ergometric test (performed in 6 subjects), we observed a plasma dopamine increase at the maximal exercise; this persisted during the early recumbent recovery phase (6 min), despite the clear-cut decrease of both norepinephrine and epinephrine plasma levels. Our data are not in agreement with previous papers describing a simple increase in plasma dopamine after stimulation. This paper provides no informations regarding the mechanisms of this response of plasma dopamine. Other approaches must be used to study this aspect more directly.

Exercise-induced ST segment depression in the diagnosis of multivessel coronary disease: a meta analysis.

To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).