Significant Ventricular Arrhythmias Research Articles

Safety of resistance training in the elderly

Disuse of skeletal muscle is often cited as a potentially reversible cause of ill health in elderly people. It can lead to a serious decline in functional health and increases the risk of outpatient care, hospitalization, nursing home admission, and death. The loss of muscle mass accounts for most of the observed loss of strength. The loss of muscle tissue is due to a decrease in the number of muscle fibers and atrophy of the type II muscle fibers. The subsequent decline in strength reduces the capacity to carry out basic activities of daily life and puts people at risk for falls, impaired mobility, and dependence [1]. Although sedentary lifestyle and aging itself may contribute to muscle weakness and loss of skeletal-muscle mass, that conditions are potentially preventable or reversible with targeted interventions [2]. It has been suggested that high-intensity resistance exercise training is a feasible and effective means of counteracting muscle weakness and physical frailty in elderly people [3]. The principal goal of resistive training in the elderly is to restore physical, psychological, and vocational function. However, resistance exercise has previously been regarded as thermodynamically hazardous due to exaggerated blood pressure responses causing higher double pressure products leading to more ischemic events. Traditionally, training programs for older subjects have emphasized lower extremity aerobic exercise (i.e., walking, stationary cycle ergometer, and stair climbing). Various vocational, recreational, and other activities of daily living actually resemble heavy resistance exercise more than aerobic exercise. Many elderly people lack the ability to perform such common activities as carrying groceries or luggage or doing yard work. Therefore, it is important to recognize that the elderly require a minimum level of muscle strength for activities of daily living. Evidence has been accumulated, which suggests that resistive exercise training may be less hazardous than was once presumed. The benefits of resistance training for the elderly are improved muscle strength and endurance, enhanced bone mineral density, weight reduction, maintaining an improved self-image, and gaining confidence. Resistance training can produce a slight increase in aerobic capacity, which is associated with the increase in muscle mass. In the elderly, exercise capacity can be limited by leg fatigue resulting in termination of exercise without coexisting evidence of cardiorespiratory limitation. Studies conducted on the elderly have demonstrated increased strength with enhanced treadmill performance in circuit weight training trainees. Therefore, those with weak leg muscles will gain additional benefits if conventional endurance training is combined with resistance training. Electrocardiographic and direct arterial blood pressure responses during single-arm and single and double-leg lifting at 20%, 40%, 60%, and 80% of one-repetition maximum (1-RM) did not reveal any clinically significant ST-segment depression, angina, or ventricular arrhythmias, except when subject were working against high resistance: 80% of 1-RM, double pressure product values exceeded those attained during cycle ergometer testing at 85% of maximal aerobic capacity. Thus, light to moderate resistive training exercise can be considered safe for low-risk cardiac patients. Even the risk of developing compromised left ventricular function is less during a workout against weight resistance compared to that in conventional clinical aerobic exercise test [7]. Eur Rev Aging Phys Act (2009) 6:1–2 DOI 10.1007/s11556-009-0047-8

Incidence and Prognostic Implication of Unrecognized Myocardial Scar Characterized by Cardiac Magnetic Resonance in Diabetic Patients Without Clinical Evidence of Myocardial Infarction

Silent myocardial infarctions (MIs) are prevalent among diabetic patients and inflict significant morbidity and mortality. Although late gadolinium enhancement (LGE) imaging by cardiac magnetic resonance (CMR) can provide sensitive characterization of myocardial scar, its prognostic significance in diabetic patients without any clinical evidence of MI is unknown. We performed clinically indicated CMR imaging in 187 diabetic patients who were grouped by the absence (study group, n=109) or presence (control group, n=78) of clinical evidence of MI (clinical history of MI or Q waves on ECG). CMR imaging and follow-up were successful in 107 study patients (98%) and 74 control patients (95%). Cox regression analyses were performed to associate LGE with major adverse cardiovascular events (MACE), including death, acute MI, new congestive heart failure or unstable angina, stroke, and significant ventricular arrhythmias. LGE by CMR was present in 30 of 107 study patients (28%). At a median follow-up of 17 months, 38 of 107 patients (36%) experienced MACE, which included 18 deaths. Presence of LGE was associated with a >3-fold hazards increase for MACE and for death (hazard ratio, 3.71 and 3.61; P<0.001 and P=0.007, respectively). Adjusted to a model that combines patient age, sex, ST or T changes on ECG, and left ventricular end-systolic volume index, LGE maintained a >4-fold hazards increase for MACE (adjusted hazard ratio, 4.13; 95% confidence interval, 1.74 to 9.79; P=0.001). In addition, LGE provided significant prognostic value with MACE and with death adjusted to a diabetic-specific risk model for 5-year events. The presence of LGE was the strongest multivariable predictor of MACE and death by stepwise selection in the study patients. CMR imaging can characterize occult myocardial scar consistent with MI in diabetic patients without clinical evidence of MI. This imaging finding demonstrates strong association with MACE and mortality hazards that is incremental to clinical, ECG, and left ventricular function combined.

Abstract 2554: Natural History of Apical Hypertrophic Cardiomyopathy: Outcome Not as Benign as Previously Suspected

Background. Apical hypertrophic cardiomyopathy (AHCM) has been considered a ``benign” form of HCM in Asian and non-Asian patients (pt). However, data on long-term outcome of pt with AHCM are limited. The purpose of this study was to determine the natural history of pt with AHCM followed at a tertiary referral center in North America. Methods. Between July 1976 and September 2006, 193 pt with the diagnosis of AHCM were seen at the Hypertrophic Cardiomyopathy Clinic. The last echocardiographic exam was reviewed in all pt. Follow-up data were obtained where possible (clinic visit). Results. Mean age at diagnosis 56±17 years, mean age at first presentation at our center was 58±17 years. Symptoms included chest pain in 69 pt (36 %), and exertional dyspnea ≥NYHA II in 97 pt (50 %). A family history of either HCM and/or sudden cardiac death was reported by 36 pt (19 %). Coronary artery disease was proven in 40 pt (21 %). Median follow up was 50 months (1–318) and obtained in 124 pt (64 %). The following events were reported at the last clinic visit: heart failure in =5 pt, syncope in =0 pt, ventricular tachycardia in =7 pt, ICD implantation in 22 pt, and stroke in 22 pt. Death from all causes occurred in 51 of 193 pt (26 %) at a mean age of 72 years (14–78). Kaplan-Meier survival analysis was used to examine survival from all causes of death since first presentation. Observed survival in patients with AHCM was significantly less than expected in an age- and gender matched Minnesota white population (p=0.009). The observed survival at 5, 10 and 15 years was 87 %, 82 %, and 57 % respectively, while the expected survival for these time points was 91 %, 81 %, and 72 %. Conclusions. AHCM in this predominantly North American patient population is associated with an increased mortality. Patients with AHCM have a high incidence of significant cardiovascular symptoms and ventricular arrhythmias. As the disease is less benign than previously suspected, careful longitudinal care by a cardiologist is warranted.

Malignant Arrhythmias Secondary to a Cardiac Fibroma Requiring Transplantation in a Teenager

We report a case of a 13-year old girl with a diagnosis of cardiac fibroma who was followed for a decade. Although she was predominantly asymptomatic over this time period, she eventually developed significant ventricular arrhythmias. The arrhythmias were originally treated with anti-arrhythmic medications along with an automatic internal cardioverter-defibrillator. However, a nearly fatal event prompted a cardiac transplantation. This represents a unique case of a patient with cardiac fibroma who was bridged to transplantation with an internal cardioverter-defibrillator.

Long-term noninvasive arrhythmia assessment after total anomalous pulmonary venous connection repair

Pediatric patients with a history of atrial surgery are at risk for the development of sinus node dysfunction and atrial arrhythmias. However, there has been no comprehensive, long-term, electrophysiologic study of patients who have undergone repair of total anomalous pulmonary venous connection. We evaluated school-aged and adolescent survivors of isolated total anomalous pulmonary venous connection repair from January 1983 to December 1996 to assess for sinus node dysfunction, atrioventricular block, and atrial and ventricular arrhythmias. Assessment was limited to an electrocardiogram, 24-hour Holter monitor, and exercise stress test. Twenty-nine children were evaluated 11.2 +/- 3.6 years after their initial operative repair. The mean age at repair was 36.0 +/- 43.0 days. Electrophysiologic studies revealed evidence of sinus node dysfunction, including sinus bradycardia, sinus pauses, and chronotropic impairment, in most of the patients. Twenty-nine percent of patients showed chronotropic impairment on exercise testing. Atrioventricular conduction abnormalities occurred in 2 patients. Single atrial and ventricular premature complexes were frequent, but complex tachyarrhythmias were less common. There was 1 patient who had nonsustained supraventricular tachycardia and 2 patients who had nonsustained ventricular tachycardia. No statistically significant relationships were found between hypothesized variables and arrhythmia outcomes. Survivors of total anomalous pulmonary venous connection repair appear to have a high incidence of signs of sinus node dysfunction and a low incidence of atrioventricular block in follow-up. Significant atrial and ventricular arrhythmias appear to be uncommon. Despite a favorable overall long-term outcome, these patients warrant ongoing clinical follow-up for arrhythmia surveillance.

An Unusual Case of Exercise-Induced Idiopathic Brugada Electrocardiographic Pattern

An exercise-induced idiopathic Brugada electrocardiographic pattern during the effort phase is very rare. A 42- year-old male visited our cardiology clinic for chest discomfort. He has been treated for myocardial infarction 2 months ago. He underwent a treadmill test according to the Bruce protocol. Typical coved-type ST-segment elevation was found during the effort phase, and it gradually recovered after the exercise. The ST-segment eleva- tion appeared to be unrelated to hypervagotonia. This elevation was not induced by a pharmacological test with flecainide. A significant ventricular arrhythmia was not induced by programmed ventricular stimulation. Hence, we discharged the patient without implantation of an implantable cardioverter defibrillator. (Korean Circulation J 2007;37:517-519)

Anesthetic management of a patient with asymptomatic ventricular tachycardia

There are many causes of ventricular arrhythmias in pediatric patients, even those with structurally normal hearts. However, in young patients with 'normal' hearts, sustained ventricular arrhythmias are relatively rare. The primary concern of the physician is to identify which patients have benign ventricular arrhythmia patterns and which are at risk for sudden cardiac death. Even in asymptomatic patients, the choice of anesthetic agents may be important to minimize precipitation of episodes of tachyarrhythmias. This clinical report describes the anesthetic considerations for an asymptomatic child with a history of sustained premature ventricular contractions, ventricular tachycardia, and bigeminy. This child had chronic serous otitis media requiring repeat tympanostomy and tube replacement. This case report outlines the initial cancellation of anesthesia because of sustained arrhythmias, and subsequent conduct of the anesthesia for the case, as well as the considerations in the selection of the drugs when a child presents with significant ventricular arrhythmia.

Prolonged Repolarization After Ventricular Assist Device Support Is Associated With Arrhythmias in Humans With Congestive Heart Failure

Background Recent observations indicate that the QTc interval often increases in the early postoperative period (<1 week) after mechanical unloading of severely failing hearts with a left ventricular assist device (LVAD). The present study examined whether early changes in ventricular repolarization after LVAD placement are associated with ventricular arrhythmias. Methods and Results An electrocardiogram was obtained within 4 days before LVAD placement, <12 hours after LVAD placement, and weekly thereafter. Patient records were reviewed for documented ventricular tachycardia (VT) or ventricular fibrillation (VF) for 1 week preoperatively and the first 2 weeks postoperatively. Differences in QTc interval between patients with and without VT were evaluated. Ten of 17 patients enrolled (59%) had VT or VF after LVAD placement. Of these, 4 required therapeutic intervention because of clinical instability or symptoms. The change in the QTc (ΔQTc) between the preoperative and immediate postoperative period was significantly different among patients with VT/VF compared with patients without VT/VF (+23 ms vs. −68 ms, P < .001). Conclusion The early period after initiation of LVAD support of the failing human heart is associated with a relatively high incidence of significant ventricular arrhythmias after LVAD placement. Beyond the impact of myocardial inflammation and wound healing occurring after all LVAD implants, early postoperative increases in the QTc interval after cardiac unloading appear to predispose to ventricular arrhythmias.

Silent Myocardial Ischemia and High-Grade Ventricular Arrhythmias in Patients on Maintenance Hemodialysis

The occurrence of silent myocardial ischemia (SMI) and serious arrhythmias during hemodialysis (HD) has been well documented. However, it is unclear whether these changes are due to epicardial coronary artery disease (CAD). We conducted a prospective study to assess whether SMI and arrhythmias during HD correlated with angiographically demonstrable CAD. Twenty-three patients with end-stage renal disease on maintenance HD underwent 48-hour Holter monitoring, beginning 24 hours prior to a HD session. All patients underwent biochemical evaluation, coronary angiography, and echocardiography. Holter monitoring showed SMI during HD in 22% cases. A significant increase in the frequency of ventricular ectopics (VEs) was noted during and after HD. Patients who showed SMI during HD and VEs prior to initiation of dialysis were more likely to develop significant ventricular arrhythmias during and after HD. Epicardial CAD was documented in four patients, and it did not correlate with SMI. To conclude, HD is an arrhythmogenic process. SMI during dialysis is probably not due to epicardial CAD but predisposes to clinically significant ventricular arrhythmias during and after HD. The cause of SMI during HD in patients without demonstrable CAD needs further investigation.

A 25-year control of idiopathic ventricular fibrillation with electrophysiologic-guided antiarrhythmic drug therapy

The case of a 28-year-old man with recurrent syncope and multiple documented episodes of idiopathic ventricular fibrillation is reported. Recurrent syncope suggesting a self-terminating ventricular tachyarrhythmia occurred after 1 month of amiodarone therapy, and ventricular fibrillation was inducible at electrophysiologic study. After addition of quinidine, no significant ventricular arrhythmias could be induced. Similar results were found during a repeat electrophysiologic study performed 23.5 years later. During a 25-year period, the patient has remained arrhythmia-free on combined antiarrhythmic medication with quinidine and amiodarone.

Autologous bone marrow (BM) stem cell transplantation into infarcted myocardium –A pilot study

6667 Background: BM stem cells have ability to differentiate into cardiac myocytes, smooth muscle cells and endothelial cells when injected into the myocardium after ischemic injury. Methods:21 patients of myocardial infarct (confirmed on stress thallium SPECT and trans-thoracic echocardiography) undergoing CABG (coronary artery bypass grafting) were studied. During CABG, BM was harvested in heparinised syringes by sternal aspirate. BM mononuclear cells (MNC) were separated using Ficoll density gradient centrifugation. At the end of the CABG, MNC were injected in and around the region of myocardial scar in 19 patients. In 2 patients stem cells were implanted through infarct related artery by coronary angioplasty. Results:The mean age of the 21 patients was 50.57years (SD =7.07) with male: female ratio of 19:2. The mean volume of BM collected was 35.33ml (SD =8.6) with a cell count of 1.3 x 107/ml (SD =2 x107). Viability of the MNC was 99% (checked by Trypan blue dye exclusion test). The MNC morphology was also seen under the light microscope by Giemsa staining and the average percentage of MNCs was 89.28 (SD=1.7). CD 34+ cells were enumerated by flowcytometry in 5 patients only, and the mean count was 0.95% (SD = 0.54). The MNCs were finally suspended in normal saline and a mean of 38+9 infarct sites were injected with 0.25ml /site. The average number of cells injected per site was 3.2 x 106. There was no adverse effect of the procedure (immediate, in-hospital or at a mean follow-up of 5.9 months + 2.8 mo). Specifically, there were no deaths and no significant ventricular arrhythmias on 24 hour holter monitoring. Initial follow-up information is currently available for the first 8 patients. There was improvement in New York Heart Association functional class (from 2.67+0.82 to 1.5+ 0.55; p=0.02) and left ventricular ejection fraction (from 30+ 13% to 42+ 10%; p=0.04). Three and 6 months follow-up data (invasive and non-invasive) is being acquired. Conclusions:This pilot study has indicated the potential safe use of the hematopoietic stem cells for repair of myocardium. No significant financial relationships to disclose.

Autologous bone marrow (BM) stem cell transplantation into infarcted myocardium –A pilot study

6667 Background: BM stem cells have ability to differentiate into cardiac myocytes, smooth muscle cells and endothelial cells when injected into the myocardium after ischemic injury. Methods:21 patients of myocardial infarct (confirmed on stress thallium SPECT and trans-thoracic echocardiography) undergoing CABG (coronary artery bypass grafting) were studied. During CABG, BM was harvested in heparinised syringes by sternal aspirate. BM mononuclear cells (MNC) were separated using Ficoll density gradient centrifugation. At the end of the CABG, MNC were injected in and around the region of myocardial scar in 19 patients. In 2 patients stem cells were implanted through infarct related artery by coronary angioplasty. Results:The mean age of the 21 patients was 50.57years (SD =7.07) with male: female ratio of 19:2. The mean volume of BM collected was 35.33ml (SD =8.6) with a cell count of 1.3 x 107/ml (SD =2 x107). Viability of the MNC was 99% (checked by Trypan blue dye exclusion test). The MNC morphology was also seen under the light microscope by Giemsa staining and the average percentage of MNCs was 89.28 (SD=1.7). CD 34+ cells were enumerated by flowcytometry in 5 patients only, and the mean count was 0.95% (SD = 0.54). The MNCs were finally suspended in normal saline and a mean of 38+9 infarct sites were injected with 0.25ml /site. The average number of cells injected per site was 3.2 x 106. There was no adverse effect of the procedure (immediate, in-hospital or at a mean follow-up of 5.9 months + 2.8 mo). Specifically, there were no deaths and no significant ventricular arrhythmias on 24 hour holter monitoring. Initial follow-up information is currently available for the first 8 patients. There was improvement in New York Heart Association functional class (from 2.67+0.82 to 1.5+ 0.55; p=0.02) and left ventricular ejection fraction (from 30+ 13% to 42+ 10%; p=0.04). Three and 6 months follow-up data (invasive and non-invasive) is being acquired. Conclusions:This pilot study has indicated the potential safe use of the hematopoietic stem cells for repair of myocardium. No significant financial relationships to disclose.

Implantable defibrillators and sudden cardiac death.

Sudden cardiac death (SCD) is among the most common causes of death in developed countries throughout the world. It is estimated that more than 3 million people die yearly from SCD, with a survival rate of less than 1%. In the United States, the Center for Disease Control recently estimated an annual incidence of 450 000 sudden deaths,1 with a survival rate of approximately 5%, although this probably is an overestimation. Although there has been a reduction in total cardiac mortality from 728 115 in 1989 to 719 456 in 1999, the percentage of deaths that are sudden has actually increased from 38% to 47%. The increase was greatest in women older than 65 years of age, from 56.3% to 63.9%. This has resulted primarily from an increase in out-of-hospital sudden deaths. There is a comparable incidence of SCD and survival rate in Western Europe.2 The magnitude of this problem can be understood by noting that SCD accounts for more deaths each year than the total number of deaths from AIDS, breast cancer, lung cancer, and stroke (Figure 1). Unfortunately, it is the first presentation of cardiac disease in 33% to 50% of patients and is 3 times as common in men than in women. Figure 1. Magnitude of the problem of sudden cardiac arrest. Coronary artery disease, with or without myocardial infarction, is by far the most common underlying disease for SCD in the western world, being responsible for approximately 75% of all SCDs.3,4 Cardiomyopathies (dilated and hypertrophic) and primary electrical heart disease account for most of the remainder. The two most important risk factors for SCD (ie, those with highest predictive value) are left ventricular ejection fraction (LVEF) less than 40% and clinical congestive heart failure.3,4 These are followed by significant ventricular arrhythmias (particularly …

Autologous human serum for cell culture avoids the implantation of cardioverter-defibrillators in cellular cardiomyoplasty

Background: Current clinical experience with cellular cardiomyoplasty (using serum bovine-cultivated myoblasts) has demonstrated significant malignant ventricular arrhythmias and sudden deaths in patients. In some ongoing clinical trials the implantation of cardioverter-defibrillator is mandatory. We have hypothesized that contact of human cells with fetal bovine serum results after 3-week fixation of animal proteins on the cell surface, representing an antigenic substrate for immunological and inflammatory adverse events. Methods and Results: Autologous myoblasts were transplanted into infarcted LV in 20 patients (90% males, mean age 62±8 years). Cells were cultivated in a complete human medium during 3 weeks, using the patients' own serum obtained from a blood sample or from plasmapheresis. Injections were performed during CABG (2.1 grafts/pt). All patients had an uneventful recovery. At a mean follow-up of 14±5 months without mortality, no malignant cardiac arrhythmias are reported. LV ejection fraction improved from 28±3% to 52±4.7% ( p=0.03), and regional wall motion score index (WMSI) from 3.1 to 1.4 ( p=0.04) in the cell-treated segments. Myocardial viability tests showed areas of regeneration. Patients moved from mean NYHA class 2.5 to class 1.2. Conclusions: A total autologous cell culture procedure was used in cellular cardiomyoplasty reducing the risk of arrhythmia. Human-autologous-serum cell expansion avoids the risk of prion, viral or zoonoses contamination. Since patients treated with noncultivated bone marrow cells are free of arrhythmia, the bovine-culture medium seems to be responsible for this complication. Cellular cardiomyoplasty may be efficient to avoid progression of ventricular remodeling and subsequent heart failure in ischemic heart disease.

Arrhythmogenic dose of epinephrine in isoflurane- or sevoflurane-anesthetized horses

SUMMARY The effect of anesthesia with xylazine-guaifenesinketamine and maintained with isoflurane or sevoflurane on the arrhythmogenic dose of epinephrine (ADE) was measured in 8 horses. The hypothesis to be tested was that the ADE for sevoflurane would not be different than the ADE of isoflurane. When horses were at a stable plane (1.25 × minimal alveolar concentration [MAC]) of inhalant anesthesia, graded increasing concentrations (0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, to a maximum of 2.0 µg/kg/min) of epinephrine were infused for 10 minutes or until 4 ventricular premature contractions (VPCs) or other serious arrhythmia occurred. The ADE was defined as the dose at which the above criteria were met or the highest dose administered. Base-apex electrocardiogram (ECG), heart rate (HR), direct arterial blood pressures, temperature, and arterial blood gases were monitored. The mean ADE for sevoflurane (4 horses = 1.31 ± 0.29, 4 horses >2.0 µg/kg/min) was not significantly different from the mean ADE for isoflurane (4 horses = 1.06 ± 0.52, 4 horses >2.0 µg/kg/min). Numerous arrhythmias were seen, and atrial fibrillation developed in 3 horses, but no horse had fatal ventricular fibrillation. Systolic pressure was significantly higher at ADE with sevoflurane than isoflurane. The dose of epinephrine required to produce significant ventricular arrhythmias (arrhythmogenic dose of epinephrine or ADE) has been used as a measure of the

Autotransplantation of unmanipulated bone marrow into scarred myocardium is safe and enhances cardiac function in humans.

Stem cell transplants into damaged myocardium may have the potential to improve cardiac function. We investigated the safety of transplanting unmanipulated autologous bone marrow into infarcted myocardium of patients undergoing coronary bypass surgery and assessed its efficacy to improve cardiac function. Fourteen patients with one or more areas of transmural myocardial infarction were studied. Autologous bone marrow was obtained by sternal bone aspirate at the time of surgery, diluted in autologous serum at a ratio of 1:2, and then injected 1 cm apart into the mid-depth of the left ventricular scar. There were no deaths, no perioperative myocardial infarctions, and no significant ventricular arrhythmias. Dobutamine stress echocardiography demonstrated overall improvement in the global and regional left ventricular function 6 weeks and 10 months after surgery. Of 34 infarcted left ventricular segments, 11 were injected with bone marrow alone, 13 were revascularized with a bypass graft alone, and 10 received bone marrow transplantation and a bypass graft in combination. Only the left ventricle segmental wall motion score of the areas injected with bone marrow and receiving a bypass graft in combination improved at low dose and at peak dobutamine stress. These findings suggest that transplantation of unmanipulated autologous bone marrow into scar tissue of the human heart is safe and enhances cardiac function only when used in combination with myocardial revascularization. This benefit can be seen after 6 weeks of the bone marrow transplant and is maintained after 10 months of follow-up.

Diabetes and haemodynamic reactions to acute coronary occlusion

Background: The risk of early sudden death before hospital admission is higher in diabetic than non-diabetic men with acute myocardial infarction and autonomic nervous activity may modify the clinical outcome of abrupt coronary occlusion. Since diabetes mellitus may interfere with autonomic and myocardial function, we decided to study whether diabetes alters autonomic and haemodynamic responses to acute coronary occlusion. Methods: We analyzed the changes in heart rate, heart rate variability and blood pressure, and the occurrence of ventricular ectopy during a 2-min coronary occlusion in 238 non-diabetic and 32 diabetic patients referred for single vessel coronary angioplasty. The ranges of non-specific responses were determined by analyzing a control group of 19 patients with no ischaemia during a 2-min balloon inflation in a totally occluded coronary artery. Results: Diabetic patients were more often ( p<0.05) female, but there were no significant differences in the occluded vessel or incidence of ST changes or chest pain during coronary occlusion between the groups. Incidence of significant heart rate reactions and ventricular arrhythmias was comparable in both groups. Systolic blood pressure decreased ( p=0.01) in the diabetic patients during coronary occlusion, but did not change significantly in the non-diabetic group. Coronary occlusion caused more often (34% vs. 14%, p<0.01) a significant decrease in blood pressure in diabetic patients . Logistic regression models developed to analyze the significance of diabetes while controlling for baseline variables and signs of ischaemia identified diabetes to be an independent predictor of hypotensive reactions (odds ratio [OR] 2.9, 95% confidence intervals 1.1–7.8, p<0.05), while female gender and high short-term heart rate variability were other independent predictors of hypotensive reactions. Conclusions: Diabetic patients often develop significant hypotension during the early phase of acute coronary occlusion. This abnormality may be related to diabetic cardiomyopathy and impairment of baroreflex-mediated regulation of circulation. Predisposition to hypotension may contribute to the observed differences in the clinical presentation and outcome of acute coronary events.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy.

The D Allele of the Angiotensin-Converting Enzyme Gene and Reperfusion-Induced Ventricular Arrhythmias in Patients With Acute Myocardial Infarction

The renin-angiotensin system may play a pivotal role in reperfusion ventricular arrhythmias (RVA). The purpose of this study was to investigate the association between angiotensin-converting enzyme (ACE) gene polymorphism and RVA in patients with acute myocardial infarction (AMI) in a case-control study. Patients who had undergone successful coronary intervention for AMI were enrolled (n= 127, male/female: 97/30, mean age, 62.6 years). The incidence of RVA was continuously monitored by ECG at a coronary care unit. The severity of ventricular arrhythmias was evaluated in terms of the Lown's grade and patients with a high risk of ventricular arrhythmias that may cause sudden cardiac death (Lown's grade > or =2) within 5 h of coronary intervention were defined as cases (n=59), and otherwise as controls (n=68). A receiver operating characteristic curve was used to determine the discriminatory ability of continuous variables and to produce dummy variables for use in a logistic regression analysis. Cases had a significantly higher body mass index, higher maximal levels of serum creatine kinase, and a shorter time preceding coronary intervention than controls. The severity of coronary atherosclerosis was similar between the 2 groups. The frequency distribution of ACE genotypes in cases differed from that in controls (II/ID/DD: 22.0%/52.6%/25.4% vs 44.1%/41.4%/14.7%, p<0.05, by the Mantel-Haenzel chi-square test). The ACE-D allele had additive and dominant effects with regard to the occurrence of significant ventricular arrhythmias after adjusting for other risk factors. The ACE-D allele may play a pivotal role in sudden cardiac death in patients with AMI.

The Hemodynamic and Holter-Electrocardiogram Changes During Halothane and Sevoflurane Anesthesia for Adenoidectomy in Children Aged One to Three Years

The Hemodynamic and Holter-Electrocardiogram Changes During Halothane and Sevoflurane Anesthesia for Adenoidectomy in Children Aged One to Three Years