Results Of Exercise Tolerance Tests Research Articles

Gauging the Positive Predictive Value of Exercise Tolerance Test Using Angiographic Evaluation: A Cross-Sectional Analysis From a Developing Country.

BackgroundExercise tolerance test (ETT) and angiographic evaluation are important tools to evaluate patients presenting with ischemic cardiac pathologies. Angiographic evaluation is regarded as the gold standard diagnostic modality to diagnose coronary artery disease (CAD). Our study aims to evaluate the positive predictive value (PPV) of ETT to diagnose CAD using coronary angiography.MethodsWe conducted a cross-sectional study that analyzed 94 patients with a positive ETT test after the application of strict inclusion and exclusion criteria. All 94 patients were referred for angiography after a positive ETT test. Data collection was performed using a structured proforma, and analysis was carried out on Statistical Package for Social Sciences (SPSS) version 23 (IBM Corp., Armonk, NY). PPV for various demographic characteristics was calculated.ResultsOut of 94 patients, 76 were males and 18 were females with a mean age of 52.28 ± 7.55 years. A total of 35.1% of the patients had type-2 diabetes, and 31.9% were hypertensive. On coronary angiography, only 25 patients had normal findings, and 69 patients had a significant occlusion in at least one of the major coronary arteries. The overall PPV of the ETT against angiographic evaluation was 73.40%. The PPV for females, hypertensives, non-smokers, and non-diabetics was lower than the PPV of males, smokers, non-hypertensives, and diabetics.ConclusionAngiographic evaluation of patients with positive ETT findings has a high likelihood of false positivity especially among females, non-smokers, hypertensives, and non-diabetics. The results of ETT must be interpreted with caution in these subsets of the population. Invasive radiological modalities can be used for diagnosis; however, such modalities do not elucidate the functioning of myocardium under stress.

Factors affecting exercise tolerance in cardiac patients at the third phase of rehabilitation

Background. Cardiovascular diseases and their complications are the top cause of death and disability; the newly developed rehabilitation methods for these conditions have to be evaluated in terms of tolerability.
 Objective. To examine the factors affecting better exercise tolerance in cardiac patients at the third phase of rehabilitation.
 Methods. The study performed at IvGMA clinic involved 34 patients undergoing the 3rd phase of rehabilitation with a diagnosis of coronary heart disease: 5 (14%) with acute Q myocardial infarction with ST segment elevation, 3 (9%) without ST segment elevation, 3 (9%) non-Q wave myocardial infarction, 23 (68%) unstable angina pectoris. The age of patients was 4976 years (average 59.47 6.08 years), of which 23 were men and 11 women. Each patient underwent a complete clinical and functional examination to assess the anthropometric data, functional indicators of the respiratory and cardiovascular systems, mental functions, and posturography. The rehab course lasted 15 days and included exercise therapy, gym machine training according to an individually designed program, and dosed walking.
 Results. Based on the results of exercise tolerance tests, we formed two case groups: patients of group 1 (n = 14) showed an improvement in the functional class of chronic heart failure according to 6-minute walking test; patients of group 2 (n = 20) showed only insignificant dynamics. Comparison of clinical and functional indicators between the 2 groups revealed that patients of group 1 had more pronounced anxiety and depressive symptoms, and a better preserved function of the respiratory system. A correlation analysis of the total sample of patients detected a correlation relationship between exercise tolerance and functions of the respiratory and cardiovascular systems, anthropometric data, and stabilogram indicators.
 Conclusions. A better exercise tolerance in patients with heart problems was associated with better baseline functions of the respiratory and cardiovascular systems, a lower body mass index, and the optimal dose of statins taken. The exercise tolerance increased in parallel with improvement of stabilogram indicators, which suggests a positive effect of targeted individual training of the equilibrium function to improve the functional result of the cardiac rehabilitation process.

Thrombosis risk factors and gene mutations in young age patients with acute coronary syndrome

Te study included 299 patients of age 25 to 44 years old with ACS were treated from 2012 to 2017 at the department of myocardial infarction 1st KGBUZ Altay regional cardiological clinic. Te middle age of patients with ACS was 40.3 ± 0.2 years. Te control group included of 53 apparently healthy volunteers aged from 25 to 44 years old, the average age those patients was 39.94 ± 0.79 years. Also, those patients hadn't any comorbid conditions. Te control group hadn't any datas of ischemic heart disease by the results of exercise tolerance tests. All patients had standard clinical, anamnestic, biochemical tests, lipid profle, fasting plasma glucose, electrocardiogram, echocardiography and coronaroangiography, also they were determined growth and weight with body-weight index. 116 patients from the ACS group and 53 patients fromthe control group had screening of polymerase chain reaction for determine polymorphism of the FII genes G20210-A, FV G1691-A, and MTHFR C677-T. We identifed the most signifcant sets of risk factors associated with ACS in young age patients based on our multifactorial statistical analysis with binary logistic regression. Tis combination of risk factors was: increased levels of low-density lipoproteins, decreased levels of high-density lipoproteins, smoking, existence of MTHFR homozygous polymorphism, heredity in combination with smoking, FV homozygote, MTHFR homozygote, smoking with MTHFR-homozygote. Te ability predicting the risk of developing cardiovascular disease in young people based on traditional risk factors, partly modifable, as well as the researching of "new" risk factors, opens up new opportunities for developing a clinical approach of treating young patients with high risk of ACS.

Diagnostic Yield of Implantable Loop Recorders in Patients with Unexplained Syncope

of patients in sinus rhythm at one and two year follow up. These results are comparable to international reports. Follow up at 12 months Follow up at ≥24 months Total (n= 65) Paroxysmal AF (n= 37) Nonparoxysmal AF (n= 28) Total (n= 36) Paroxysmal AF (n= 20) Nonparoxysmal AF (n= 16) Success without drugs Single procedure (%) 53.8 56.8 50.0 50.0 55.0 43.8 Success with or without drugs Single procedure (%) 58.5 59.5 57.1 50.0 55.0 43.8 Success without drugs ≥1 procedure (%) 69.2 67.6 71.4 69.4 70.0 68.8 Success with or without drugs ≥1 procedure (%) 89.2 91.9 85.7 86.1 90.0 81.3 http://dx.doi.org/10.1016/j.hlc.2012.03.098 Diagnostic Yield of Implantable Loop Recorders in Patients with Unexplained Syncope J. Swampillai ∗, R.F. Allen, S. Levings, M.R.Webber, C.M. Wade, M.K. Stiles, S.C. Heald Department of Cardiology, Waikato Hospital, Hamilton, New Zealand Background: The implantable loop recorder (ILR) is a subcutaneous, electrocardiographic monitoring device used for diagnosis in patients with recurrent, infrequent Use of Exercise Tolerance Test in Intermediate Risk nonST Elevation Acute Coronary Syndrome P. Tamuno ∗, J. Mazhar, J. Swampillai, V. Pera, A. Kerr, G. Devlin Department of Cardiology, Waikato Hospital, Hamilton, New Zealand Background: Exercise tolerance test (ETT) is recommended for initial risk stratification in patients with Non ST Elevation Acute Coronary Syndrome (NSTEACS) in the absence of high risk features. We reviewed current practice at Waikato Hospital, the regional tertiary centre. Methods:FromtheACUTEPREDICTregistrywe identified 716 patients admitted with NSTEACS and TIMI score 0–4 between January 2008 and January 2010. After excluding143patientswhoweremanagedmedically (20%)due to co-morbidities, the remaining 573 patients were analysed in two groups: Group A had ETT prior to angiography; Group B had angiography without ETT. Results: There were 244 (43%) patients in Group A (mean age 64± 12 years, 72% males) and 329 (57%) in Group B (mean age 64± 13 years, 66% males). Compared togroupA,GroupBhadmorepatientswithTIMI score 3–4 (63%vs. 53%,P= 0.02) andNSTEMI (66%vs. 44%,P≤ 0.01). Results are summarised in the tables below. Only 20% of patients risk-stratified by ETT did not undergo inpatient angiography (Tables 1 and 2). symptoms with a suspected arrhythmic aetiology. We aimed to establish the diagnostic yield of ILR in patients with unexplained syncope. Methods: We identified all patients who had an ILR implanted at Waikato Hospital from March 2007 to November 2011. Previous investigations, arrhythmias detected by the device and outcomes were recorded. Results: Thirty-one patients (17 men; mean age 46± 24 years) underwent ILR implantation. The mean number of cardiac investigations prior to ILR was 4± 1; duration of implant 16± 12 months. Arrhythmias were detected in 13 patients; eight tachycardias, five bradycardias. Time to diagnosis was 7± 6 months and specific treatment was guided by ILR analysis in these patients. Pacemakers were implanted in four patients, two received implantable cardioverter defibrillators, two were given anti-arrhythmic drugs, four had an electrophysiological study (two were normal and two underwent catheter ablation). Neurocardiogenic syncope was diagnosed in one patient and symptoms resolved. Sinus rhythm was documented during syncope in five patients. Death from non-arrhythmic causes occurred in twopatients (onemyocardial infarction and cardiogenic shock, one stroke). No arrhythmias have been detected so far in 11 patients remaining under follow up (mean implant duration 9± 7 months). Conclusion: More than half of patients had an arrhythmic causeof syncopediagnosed (13) or excluded (5) by ILR. This confirms their usefulness in selected patients with unexplained syncope despite normal preliminary investigations. http://dx.doi.org/10.1016/j.hlc.2012.03.099 Table 1. Summary of coronary interventions and outcomes. Group A N= 244 Group B N= 329 P value Inpatient angiogram 195 (80%) 329 (100%) <0.01 PCI 109 (45%) 180 (55%) 0.02 CABG 23 (9%) 24 (7%) NS Length of stay in days (mean±SD) 6.8± 6 6.1± 5 0.09 Stroke/TIA (in-hospital) 0 3 Death (in-hospital) 1 1 Table 2. Angiograms performed in relation to ETT results. Positive ETT N= 167 (68%) Negative ETT N= 42 (18%) Inconclusive ETT N= 35 (14%) In-patient angiogram, N (%) 159 (95%) 10 (24%) 26 (74%) Angiogram in 6-month F/U, N (%) 6 (4%) 7 (17%) 2 (6%) Conclusions: The majority of patients admitted with NSTEACS and TIMI score ≤4 underwent inpatient angiography regardless of the use of ETT as a risk stratification tool for intermediate risk scores. No difference was evident in early events. http://dx.doi.org/10.1016/j.hlc.2012.03.100

Usefulness of ST segment depression limited to the recovery phase of exercise stress test.

To determine the diagnostic value of ST segment depression limited to recovery phase of Exercise Tolerance Test (ETT). An observational cross-sectional study. The study was carried out at Punjab Institute of Cardiology, Lahore, from March to August 2007 for a period of 6 months. In this study, 100 patients were selected with purposive non-probability sampling technique and were divided into two groups, group A having ST segment depression during exercise phase of ETT, and group B having ST segment depression only in recovery phase after undergoing ETT according to Bruce protocol. The patients were subjected to coronary angiography later on. The chi-square or Fischer's exact test of significance was applied at 0.05 level of significance to compare the coronary angiographic finding between two groups. Diagnostic value of ST segment depression was computed keeping angiographic finding as Gold standard. There were no major differences between the two groups regarding angiographic finding. Significant coronary artery stenosis (> 50% narrowing) was found in 68 (93%) patients of group A and 23 (85%) patients of group B (p=0.18). Three vessel disease was found in 30 (41%) patients in group A and 7 (26%) patients in group B (p=0.08). Left main stem disease was found in 5 (6.8%) patients of group A and 1 (3.7%) patient of group B. Normal coronaries were found in 6% of patients among group A and 14% of patients among group B (p=0.12). Specificity, sensitivity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of ST segment depression in recovery phase was 55, 25, 85 and 6 percent respectively (95% CI; 1.16 - 2.25). In patients undergoing exercise stress test, ST segment depression occurring only in recovery phase of ETT has a diagnostic value largely comparable with that of ST segment depression induced during exercise phase of ETT. Thus careful evaluation of ST segment depression occurring only in recovery phase may add significantly to the clinical information derived from the results of ETT.

Yield of nuclear scan strategy in chest pain unit evaluation of special populations

Patients with chest pain (CP) and nondiagnostic ECG represent heterogeneous population in whom the evaluation of coronary risk factors including metabolic syndrome (MetS) and diabetes mellitus (DM) might improve risk stratification. We enrolled 798 consecutive CP patients; 14% presented with MetS and 10% with DM; the remaining 76% presented with other coronary risk profiles (others). All patients underwent maximal exercise tolerance test (ETT) and myocardial perfusion imaging (exercise-MPI). Those with positive testing underwent angiography, whereas the remaining patients were discharged and later followed up. Primary end-point was a composite of coronary stenoses greater than or equal to 50% documented by angiography or coronary events at follow-up. Patients with MetS or DM had significantly lower survival free from end-point than those patients without (P<0.001). Exercise-MPI showed high negative predictive value in MetS, DM, and others (>96%); however, positive predictive value was 69, 74, and 52%, respectively (P<0.05). ETT alone showed negative predictive value (88%) which was significantly lower than exercise-MPI (98%), (MetS vs. others: P<0.001, and DM vs. others: P=0.05). The area under the receiver-operating characteristic curves obtained from the multivariate model includes clinical data alone, clinical data and ETT results, or clinical data and exercise-MPI results increase progressively. A nuclear scan strategy in special populations, including CP patients with MetS or DM, is a valuable tool for risk stratification and adds incremental prognostic value over clinical and ETT values.

Excellent Midterm Outcome of Extracardiac Conduit Total Cavopulmonary Connection: Results of 126 Cases

Extracardiac conduit total cavopulmonary connection has shown good early results; however, its long-term outcome has yet to be reported. Of 282 patients who underwent extracardiac conduit total cavopulmonary connection since 1994, 126 patients who have been followed up for more than 5 years were included in this retrospective study. Actuarial survival rate, incidence of late complications, hemodynamic variables, and results of exercise tolerance test were reviewed. Follow-up time was 96.4 +/- 23.0 months. There was 1 operative death and 6 late deaths. Actuarial survival rate was 95.2% and 93.6% at 5 and 10 years, respectively. Seven patients had late complications including new-onset supraventricular arrhythmia in 3, protein-losing enteropathy in 2, thromboembolism in 1, and bleeding complication in 1. Seven patients underwent reoperation not related to the conduit. Freedom from Fontan-related events was 88.8% at 5 years and 84.3% at 10 years. Late cardiac catheterization in 119 survivors showed central venous pressure of 9.9 +/- 2.9 mm Hg, cardiac index of 3.6 +/- 0.8 L x min(-1) x m(-2) and arterial oxygen saturation of 94.5 +/- 2.3%. No patient showed conduit stenosis. Plasma concentration of atrial and brain natriuretic peptide (pg/mL) were 28.9 +/- 20.0 and 25.8 +/- 44.5. Exercise test performed in 101 patients showed endurance time of 75.7 +/- 12.9% of normal value, peak heart rate of 92.3 +/- 14.4% of normal, and peak oxygen consumption of 90.0 +/- 20.0% of normal. The latest echocardiogram showed ejection fraction of 60.4 +/- 11.7%. Three patients had pacemaker rhythm, 1 had junctional rhythm, and 115 patients had sinus rhythm. Midterm outcome of extracardiac conduit total cavopulmonary connection was satisfactory with low incidence of late mortality and morbidity, and excellent hemodynamic state.

Nicorandil. An updated review of its use in ischaemic heart disease with emphasis on its cardioprotective effects.

Nicorandil is a drug with both nitrate-like and ATP-sensitive potassium-channel (K+ ATP) activating properties. By virtue of this dual mechanism of action, the drug acts as a balanced coronary and peripheral vasodilator and reduces both preload and afterload. The K+ ATP channel has been shown to be involved in the phenomenon of myocardial preconditioning, and studies in animal models of ischaemia-reperfusion-induced myocardial stunning or infarction indicate that nicorandil has cardio-protective effects. Studies in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) have shown that the administration of nicorandil reduces ST-segment elevation during ischaemia. Nicorandil significantly improved the results of exercise tolerance tests versus baseline in patients with stable effort angina pectoris in early noncomparative trials. The drug also improved the results of exercise tolerance tests relative to placebo in early randomised, double-blind, placebo-controlled trials. In randomised, double-blind comparative studies in patients with angina pectoris, nicorandil has demonstrated equivalent efficacy, as measured by exercise tolerance testing, to isosorbide di- and mononitrate, metoprolol, propranolol, atenolol, diltiazem, amlodipine and nifedipine. The effects of nicorandil on various aspects of myocardial recovery from ischaemic damage caused by acute myocardial infarction have been investigated in the short term. Regional left ventricular (LV) wall motion, a marker of myocardial function, was significantly improved in nicorandil recipients relative to control. The main adverse event associated with nicorandil as treatment for angina pectoris is headache. This can be minimised by commencing nicorandil at a low dose in patients prone to headache. There have been infrequent case reports of mouth ulcers in patients receiving nicorandil; causality has not been conclusively established, but product prescribing information indicates that an alternative treatment should be considered if persistent aphthous or severe mouth ulceration occurs. Thus, nicorandil remains a useful background therapy for patients with angina pectoris. The drug has also demonstrated potential cardioprotective effects when used as part of an intervention strategy directly after acute myocardial infarction in high-risk patients. Further large scale longer term studies of nicorandil in this latter indication are awaited with interest.

Women with chest pain: is exercise testing worthwhile?

To determine the diagnostic value of the exercise tolerance test (ETT) in women presenting with chest pain. Prospective study of all women presenting to a centre with chest pain between 1987 and 1993 who were assessed by an ETT and coronary angiography. The outpatient clinic of one consultant cardiologist in a tertiary referral centre. All women referred to this outpatient clinic with chest pain were screened. For inclusion, patients had to perform ETT and undergo coronary angiography. Of the 347 referred during this period, 142 were excluded because they were unable to perform ETT or because of Q waves or other abnormalities on their resting electrocardiogram. Overall the sensitivity of the ETT was 68% and the specificity was 61%, with a positive predictive value of 0.61 and a negative predictive value of 0.68. There were 42 false positive and 31 false negative ETT results (36% of the study group). The predictive value of a negative test was higher in younger women (< 52 years) than in the older group (> or = 52 years) (P = 0.004), but the positive predictive value in the two groups was not significantly different. The predictive value of a negative test was also higher in those with two or fewer risk factors than in those with three or more risk factors (P = 0.001). The negative predictive value for those women above 52 years with three or more risk factors (24% of the study group) was only 0.25. Lack of chest pain during ETT was associated with a higher negative predictive value in the younger group than in the older women (P = 0.006). In women with chest pain use of the ETT was a misleading predictor of the presence or absence of coronary disease in 36% of these patients. In particular, a negative test in older women with three or more risk factors had a very low predictive value. The inclusion of risk factors and division by age can, however, be used to identify a population at intermediate risk for coronary artery disease in whom the ETT result has the highest diagnostic utility.

Coronary dissection: A predictor of restenosis?

To determine if arterial dissection resulting from transluminal coronary angioplasty (TCA) leads to a greater incidence of restenosis, 273 consecutive patients who had undergone TCA with at least 1 year of follow-up were examined. Success was graded as a ≥20%. Increase in intraluminal diameter. Dissection was defined as a prominent intimal defect at the site of angioplasty. Restenosis was defined as a 50% loss of the initial angiographic gain. Of 216 patients in whom TCA was successful, 64 (30%) had dissections at the site of angioplasty and 152 (70%) had no dissection. During follow-up, 135 patients were asymptomatic with normal results of exercise tolerance tests, recurrent symptoms developed in 81 patients, and 64 patients underwent repeat angiography. The overall restenosis rate was 21%. In the dissection group, 11 (18%) had documented restenosis and 49 (82%) did not develop restenosis. In the nondissection group, 35 (24%) had documented restenosis and 113 (76%) did not develop restenosis. These data show that patients who develop dissections at the time of TCA are no more likely to develop restenosis during follow-up.

Total correction of tetralogy of Fallot in adults.

A series of 42 patients who underwent total correction of tetralogy of Fallot as adults is presented. Previous palliative operation had been performed in 33 cases: Blalock-Taussig shunt in 28 (bilateral in 6), Brock operation in four and Potts' anastomosis in one case. Severe cyanosis (average hemoglobin 203 g/l), thrombotic complications and hypoxic spells were the most pertinent of the clinical manifestations necessitating the total repair. Blalock-Taussig shunt had closed spontaneously before the intracardiac operation in 14 cases (3 bilateral) and in 11 it was ligated. In six cases the shunt was left untreated, being hemodynamically insignificant at operation. Three of the 42 patients died in association with the intracardiac operation. A-V block developed in two patients and required permanent pacemaker. During follow-up periods of up to 13 years, a residual ventricular septal defect was found in seven patients. Two of the defects were surgically closed. Five were not corrected, as the patients were doing well and the pulmonary/systemic flow ratio was less than 1.5 at repeat catheterization. Two-thirds of the patients were in NYHA class I at re-examination, and the others were in class II. The subjective functional improvement was greater than could have been expected from results of exercise tolerance tests.

EXERCISE TOLERANCE TESTS ON PATIENTS WITH MYOCARDIAL INFARCTION

The cardiac function of the patients with myocardial infarction was examined by the quantitative exercise tolerance test with an ergometer at discharge. Results of the tests were compared with clinical findings in the acute stages and clinical records during their hospitalization.52 male patients with average age of 58, who were admitted due to acute myocardial infarction, were examined in this study. At the time of discharge, an intermittent multiple load test (25W, 50W, 75W and 100W for five minutes each) was conducted using a bicycle ergometer in the upright position. ST changes of more than 2mm compared to the level at rest, frequent extrasystoles, and appearances of marked arrhythmias on the electrocardiographic recordings were the criteria for discontinuation of loading. Subjective symptoms as the criteria for discontinuation included appearance of chest pain, dyspnea, or high degree of fatigue in legs. Clinical findings in their acute stages and clinical records during their hospitalization were compared and examined in relation to the results of exercise tolerance test for each case aforementioned.The maximum physical work capacity (max. P. W. C.) at discharge, that was at around ten weeks after the attack of myocardial infarction, was 25W for 18 of 52 cases (group I), 50W for 18 cases (group II), and 75W or higher for 16 cases (group III), being almost equally divided to one third. Tests with 100W loading were performed in 9 cases in the group III, showing 3 cases with max. P. W. C. of 75W, and 6 cases with max. P. W. C. of 100W or higher.Groups with poor cardiac function at discharge were composed of cases with old age, extensive infarction, reattack, heart failure, arrhythmia, or with interfering factors for rehabilitation.Durations of bed rest were 30, 23, and 17 days for group I, II, and III, respectively. Periods of hospitalization were 86, 68, and 51 days for these groups, respectively. Both were apparently longer in groups with poorer cardiac function.Young patients, patients with limited infarction, or initial attack, or with good clinical findings, or without interfering factors for rehabilitation showed good cardiac function despite of relatively short period of hospitalization. Early mobilization and discharge after myocardial infarction should be recommended to such cases.

Effect of exercise on electrocardiograms of patients with low serum potassium.

Twelve adult patients (10 hypertensive and two normotensive) with low serum potassium levels but without electrocardiographic signs diagnostic of hypokalemia were subjected to nonstrenuous exercise. Electrocardiographic signs of hypokalemia appeared following exercise in all but the two hypertensive patients receiving digitalis. The severity of the changes and the duration correlated with the degree of hypokalemia present prior to exercise. The results were similar in the normotensive and hypertensive patients and in those made chronically or acutely hypokalemic. Following potassium repletion, exercise did not produce electrocardiographic changes of hypokalemia. The frequency with which S-T segment and T-wave changes occurred following exercise during potassium depletion suggested that hypokalemia can introduce an error in interpreting results of exercise tolerance tests in patients receiving thiazide compounds, when serum potassium is at the low normal or borderline level. These results may reflect intracellular myocardial potassium depletion brought on by exercise.