Impaired holter-derived variables of parasympathetic activity in diabetic patients with daily-life silent myocardial ischemia

To evaluate Holter-derived variables of impaired parasympathetic activity in diabetic patients with silent myocardial ischemia. Cross sectional nature cohort study. Department of Medicine, Farwania Hospital, Kuwait. One hundred and sixty patients with diabetes mellitus. 24-hour Holter electrocardiography [ECG] monitoring was used for heart rate variability and silent myocardial ischemia. Predictive indices revealed that Holter derived variables of parasympathetic activity [p-NN50, rMMD, SDANN-i] are considered as indicators for prediction of likelihood of daily life silent myocardial ischemia in diabetic patients. Sensitivity was 86, 85, 82%, specificity=88, 89, 81%, accuracy = 87, 86, 87%, positive predictive value = 89, 90, 86% and negative predictive value = 84, 83, 81% respectively. Multivariate analysis revealed that duration of diabetes status and serum level of HbA1c, as independent variables were associated with likelihood of daily life silent myocardial ischemia [p < 0.05]. Receiver operating characteristic [ROC] curve data revealed that the best cut-off value of p-NN50 was 8% with sensitivity = 86% and false positive = 16%, [rMMD] = 26 msec with sensitivity = 85% and false positive =15% and [SDANN-i] = 96 msec with sensitivity = 81% and false positive = 21% for prediction of likelihood of daily life silent myocardial ischemia in diabetic patients. Silent myocardial ischemia in diabetic patients provides statistically significantly association with impaired parasympathetic activity

External non-invasive cardiac pacemaker: evaluation of usefulness, function and capture failure rate

To evaluate the clinical usefulness, safety and efficacy of the non-invasive temporary pacemaker [NTP]. Cohort observational study Settings: Department of Medicine, Farwania and Sabah Hospitals, Kuwait. One hundred and forty patients who presented with asystolic cardiac arrest and symptomatic bradyarrythmias Interventions: Application of a NTP that functions as VVI demand pacemaker with separate external pacing and sensing electrodes. Evaluation of pacemaker capture done by palpating carotid artery pulse, non-invasive blood pressure recording and transthoracic echocardiography. Out of 140 patients, only 76 patients responded well to NTP. Predictive indices revealed that dilated cardiomyopathy is considered as negative predictor for the failure of NTP to capture the ventricle. Sensitivity was 73%, specificity = 90%, accuracy = 78%, positive predictive value = 95% and negative predictive value = 59% respectively. Multivariate analysis revealed that chronic obstructive pulmonary disease [COPD] status, left ventricular ejection fraction [LVEF], serum potassium, chest size and left ventricular end diastolic dimension [LVEDD] as independent variables were negative predictors for failure of NTP to capture the ventricle [p < 0.05]. Receiver operating characteristic [ROC] curve data revealed that the best cut-off value for serum potassium was 3.0 mmol/1 with a sensitivity = 77% and false positive - 24%, LVEF - 15% with sensitivity = 84% and false positive = 19% and LVEDD = 7.6 cm with sensitivity = 74% and false positive = 28% to predict the failure of NTP to capture the ventricle. Transcutaneous pacemaker appears to offer benefit and may become an important tool in the management of patients with symptomatic bradycardia and asystolic cardiac arrest

Coronary artery ectasia: a case report and review of literature

Coronary artery ectasia is not an uncommon diagnosis and is well described in the literature in large-scale reports. Two patients presented with chest pain and positive stress ECG test for reversible ischemia. Coronary angiogram showed coronary artery ectasia with no obstructive coronary artery disease. Only medical treatment was recommended

Early improvement of infarct-associated mitral valve regurgitation and likelihood of successful thrombolysis: color doppler echocardiographic study

To determine whether early successful thrombolysis can improve infarct-associated mitral valve dysfunction. Cohort study conducted between February 1997 and January 2004. Coronary care unit and non-invasive cardiac laboratory, Department of Medicine, Farwania hospital, Kuwait. One hundred and twenty five patients with ST segment elevation and acute myocardial infarction associated mitral valve regurgitation/ mitral regurgitation [MR] were included in the study. Cardiac enzymes and 12-lead electrocardiogram were done for all patients. Transthoracic echocardiography, pulsed Doppler and color Doppler echocardiogram were done on admission and within 24 hours after thrombolytic therapy. Infarct-associated MR in hospital outcome. Predictive indices revealed that the early improvement of infarct-associated MR after thrombolytic therapy is an indicator to predict successful thrombolysis status. The sensitivity was 86%, specificity = 79%, accuracy = 83%, positive predictive value = 62% and negative predictive value = 38%. Step wise logistic multivariate analysis revealed a significant correlation between the age of the patients, chest pain to thrombolytic therapy interval and the early improvement of MR after thrombolytic therapy of acute myocardial infarction [p < 0.05]. Patients with post-thrombolysis improvement in MR had a significantly lower incidence of in-hospital post-infarction angina, reinfarction, sustained ventricular tachycardia and congestive heart failure than patients without improvement [p < 0.05]. Early improvement of infarct-associated MR in patients with acute myocardial infarction treated with thrombolytic therapy suggests successful thrombolysis

Predictive accuracy of tissue Doppler imaging for assessment of noninfarct myocardial region in patients with acute myocardial infarction

To investigate the value of pulsed tissue Doppler imaging [TDI] in order to predict significant coronary artery stenosis supplying the noninfarct region in patients after acute anterior myocardial infarction. Transthoracic echocardiography and coronary angiography were performed on 220 patients with acute anterior myocardial infarction. The TDI-derived variables of the mitral valve annulus in the noninfarct region, systolic velocity [Sm], early diastolic velocity [Em] and late diastolic velocity [Am], were estimated in centimeters per second, and the Em/Am ratio was calculated. Predictive indices revealed that the impaired TDI-derived variables, Sm, Em, Am and the Em/Am ratio, were an indicator for predicting significant coronary stenosis in the noninfarct region. Multivariate analysis revealed that the impaired Sm and Em velocities were significantly associated with age of the patients, coronary collaterals and infarct-related artery stenosis [p < 0.05]. Receiver-operating characteristic curve data of TDI-derived variables for prediction of significant coronary stenosis revealed that the cut-off values of Sm, Em, Am and Em/Am ratio were 7.2 cm/s, 6.4 cm/s, 12.1 cm/s and 0.56, respectively. The K coefficient value indicated that there was an agreement between coronary angiography and the TDI-derived variables Sm, Em, Am and Em/Am ratio in noninfarct regions [K = 0.770, 0.731, 0.693 and 0.679, respectively]. There was a significant correlation between the severity of coronary artery stenosis [independent variable] and impaired Sm and Em/Am ratio [dependent variables], y = 11.5 - 0.05x, r = -0.902, [p < 0.05], and y = - 0.14x + 1.87, r = -0.754, [p < 0.05], respectively. TDI can be used to identify patients with significant stenosis of the coronary arteries supplying the noninfarct region and consequently may be helpful in considering patients for coronary angiography in the early postinfarction period

Early changes in ventricular repolarization after thrombolytic therapy in patients with acute myocardial infarction as indicators for prediction of epicardial coronary artery reperfusion

To investigate the relationship between early T-wave inversion after thrombolytic therapy and the likelihood of successful epicardial coronary reperfusion. Thrombolytic therapy was given to 195 patients with ST segment elevation due to acute anterior myocardial infarction [AMI]. Coronary angiography was performed. Receiver operating characteristic [ROC] curve [grade of sensitivity versus false positive] was calculated using likelihood ratio method to identify the ideal cut-off values of the ventricular repolarization variables. Predictive indices showed 80% sensitivity, 83% specificity, 81% accuracy, 88% positive predictive value and 71% negative predictive value for early T-wave inversion after thrombolytic therapy. A good concordant agreement was noted between the data of coronary angiography and early T-wave inversion in the infarct-related ECG leads after thrombolysis [kappa coefficient x = 0.876]. Stepwise multivariate analysis revealed that early T-wave inversion after thrombolytic therapy of AMI was significantly associated with a history of preinfarction angina, residual infarct-related coronary artery stenosis >50%, short time to thrombolytic therapy <90 min, and evening time for occurrence of thrombolysis [p < 0.05]. The ROC curve data analysis showed that early T-wave inversion amplitude after AMI had 87% sensitivity and 84% specificity for predicting successful reperfusion, with an ideal cut-off value of 7.2 mm, while time of T-wave inversion had 80% sensitivity and 79% specificity, with an ideal cut-off value of 120 min. The data indicate that early inversion of T wave after AMI is a statistically significant independent variable in predicting successful epicardial coronary thrombolysis status

Single photon emission computed tomography of technetium 99m tetrofosmin myocradial perfusion imaging in patients with sytemic lupus erythematosus: a preliminary report

This study was to evaluate the utility of single-photon emission computed tomography [SPECT] of Technetium 99m tetrofosmin [Tc-99m TF] myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus [SLE] Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardia] perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TP myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs

Utility of exercise electrocardiographic stress test for assessment of cardiac autonomic function in hypertensive patients

To evaluate the usefulness of recovery time after a treadmill exercise ECG test for assessment of autonomic function in hypertensive patients using Holter-based heart rate variability as a reference. One hundred untreated hypertensive patients were included in the study. Echocardiography was done to assess left ventricular mass index and function. Exercise ECG test was done in all patients. The heart rate recovery was calculated as the reduction in heart rate from its peak value to one minute of the recovery time. A cut off value of 12 beats/minute or less was considered abnormal. The patients were classified into two groups; Group I: included 70 patients with impaired heart rate variability and Group II: included 30 patients with normal heart rate variability. Holter 24 - hour ECG monitoring was done in all patients for assessment of heart rate variability. There was a significant impaired heart rate variability in hypertensive patients, with impaired heart rate recovery than in those with normal heart rate recovery [p<0.05]. Predictive indices of heart rate recovery after exercise ECG test, for assessment of cardiac autonomic function revealed a sensitivity of 74%, specificity of 83.3%, positive predictive value of 91.5%, negative predictive value of 58.2% and an accuracy of 77%. Stepwise logistic analysis revealed a significant relation between the maximal heart rate during exercise test, time-domain heart rate variability variables [r-MSSD and p-NN50] and impaired heart rate recovery after exercise ECG test in hypertensive patients [p<0.05].There was a significant correlation between Holter based vagal dependent r-MSSD and the heart rate recovery after exercise test [p<0.05]. Incorporation of heart rate recovery after e x e rcise may eventually be considered an useful diagnostic test for assessment of autonomic nervous system function in hypertensive patients

QT dispersion Immediately after exercise test improves sensitivity and specificity for diagnosis of ischemic heart disease

To evaluate the validity of QT-dispersion immediately after a treadmill exercise electrocardiography [ECG] test for diagnosis of ischemic heart disease in the presence or absence of exercise induced significant ST-segment depression. We studied 80 patients [70 men and 10 women] without history of myocardial infarction [MI]. All patients underwent treadmill exercise ECG test and coronary angiography. The patients were classified into two groups: Group I: included 30 patients with normal coronary angiography and Group II: included 50 patients with angiographically documented coronary artery disease [CAD]. There was a significant increased QT dispersion [p < 0.05] immediately after exercise and a significant ST segment depression [p < 0.05] in patients with CAD than those with normal coronary artery, but no significant difference at baseline and after six minutes during recovery [p = NS]. Predictive indices revealed that QT dispersion immediately after exercise was a valid indicator for prediction of ischemic heart disease. Its sensitivity was 80%, specificity 83%, accuracy 81%, positive predictive value 88% and negative predictive value 71%. There was a significant correlation between coronary artery stenosis and QT dispersion immediately after exercise [r = 0.786 and p < 0.01] and QT dispersion [60 ms] corresponded to coronary artery stenosis [70%] in patients with single vessel disease. There was a good agreement between two observers and no significant difference as regards intraobserver and interobserver variability. Stepwise logistic multivariate analysis revealed a significant relation between hypertension status, left ventricular hypertrophy and increased QT dispersion immediately after exercise test in patients with CAD [p < 0.05]. QT dispersion, immediately after exercise is a clinically useful marker of exercise induced myocardial ischemia independent of the presence or absence of exercise-induced significant ST-segment depression

Utility of transtelephonic electrocardiographic Transmission system for detection of ischemic ST-segment during exercise stress test

To confirm or deny the hypothesis that the transtelephonic electrocardiographic [ECG] transmission system is useful for the detection of ischemic ST-segment during exercise in patients with typical chest pain. Prospective clinical study. Non-invasive Cardiac Unit, Department of Medicine, Farwania Hospital, Kuwait. One hundred patients with chest pain were included in the study but only 60 were patients with angiography documented coronary artery disease. All the patients underwent treadmill exercise ECG test. Transtelephonic ECG transmission system was provided for all the patients during their exercise ECG test. Simultaneous transtelephonic recording yielded 15 out of the 35 patients with a ST segment depression at peak exercise [sensitivity = 42%]. Out of 60 patients with a negative ST segment response to exercise test, only five patients [false positive] had a 1 mm ST segment depression detected on transtelephonic system [specificity = 92%]. There were 20 false negative transmissions on transtelephonic recorder when the ST segment response to exercise test was positive. But in the patient group that underwent coronary angiography, there was an increase in sensitivity [60%] and specificity [100%] of transtelephonic re c o rder in detecting the ischemic ST segment, as there were no false positive results. With regard to detection of ventricular arrhythmias, the transtelephonic system had 100% sensitivity and specificity. Stepwise logistic analysis showed no significant relation to age, gender, body mass index, history of myocardial infarction, diabetes mellitus status and hypertension as independent variables [p = NS]. Transtelephonic system tended to underestimate the peak amplitude of the ST segment depression as compared to the maximal ST segment depression observed during exercise test [1.22 +/- 0.21 versus 1.81 +/- 0.43 mm, p<0.05]. There was no significant correlation between ST segment depression observed by exercise test and transtelephonic system [r = 0.582, p = NS]. Despite the limitations and the confounders of our approach, this study suggests a limited value of this small monitor for the outpatients awaiting episodes of chest pain. Further studies are needed to clarify the validity and reliability of this diagnostic tool in these clinical settings

Laser management of subglottic stenosis

This study aimed to evaluate the use of laser in treating subglottic stenosis. The study included ten patients suffering from laryngeal stenosis of various etiologies. The stenosed segments were excised using CO2 laser. Successful improvement in respiration occurred in eight patients during the follow up period [six months]. Decannulation was performed in four cases out of the six tracheostomized patients. It was believed that laser seems to be an excellent method to manage subglottic stenosis especially when the stenosed segment is less than 1 cm in length