Goal Heart Rate Research Articles

Cardiac ischemic symptoms among diabetic patients with their exercise tolerance test findings at a tertiary care hospital of Bangladesh

Background: Cardiovascular disease is the leading cause of death among diabetic patients. Diabetics who experience chest pain should get a full cardiac evaluation. Exercise tolerance test (ETT) is a noninvasive, less costly and relatively accurate test for evaluation of ischemic heart diseases. This study aimed to describe cardiac ischemic symptoms among diabetic patients and their ETT findings. Methods: This cross-sectional study was carried out among 82 diabetic patients with ischemic symptoms, in the Department of Cardiology, BIRDEM General Hospital, Dhaka from July to December 2018. Results: The mean±SD age was 60.91±11.68 years with male predominance (67%). The respondents had diabetes for an average of 8.34±4.92 years. Two-thirds of research participants were on insulin. The majority of the resting ECG results were ST-T changes (86.58%); mostly in anterior leads (54.9%) and ‘T’ inversion was predominant feature (64.2%) among all ST-T changes. The ETT result was positive in 69.72% of the individuals. During the ETT test, 57.31% of the individuals reached their goal heart rate. Test was terminated owing to tiredness in the majority of the individuals (86.58%). Chest pain and shortness of breath were significantly higher (p 0.042 and 0.011 respectively) in ETT positive participants. Aside from diabetes, the ETT positive participants had risk factors such as dyslipidaemia, hypertension, a family history of IHD and smoking (18.3%, 8.53%, 14.63% and 13.42% respectively). Conclusion: Over two-thirds of the diabetic patients with suspected IHD had positive ETT findings in this study. BIRDEM Med J 2023; 13(2): 67-75

Abstract 14066: Control of Atrial Fibrillation With Short vs Long Duration of Continuous Intravenous Diltiazem

Introduction: Continuous intravenous (IV) diltiazem is one of the options for urgent management of atrial fibrillation with rapid ventricular response (RVR). This study assesses the clinical outcomes of utilizing IV diltiazem for less than or greater than 24 hours. Methods: A retrospective chart-review of patients receiving continuous IV diltiazem between January 1, 2017 and December 31, 2018 where adult patients were included if they had atrial fibrillation with RVR and were treated with continuous IV diltiazem. Exclusion criteria included initiation of IV diltiazem in the ICU, strict nothing by mouth, only a bolus of IV diltiazem used, no conversion to oral rate controlling agent following discontinuation of IV diltiazem, and if pregnant. Infusions lasting >24 hours and <24 hours were compared. Primary objective was to evaluate duration in goal heart rate for the first 48 hours after conversion to PO diltiazem. Secondary outcomes included length of hospitalization, ICU transfer, 30-day readmission, and development of cardiovascular events including stroke, myocardial infarction, or cardiovascular death. Results: 146 out of 251 patients met inclusion criteria. 75.3% of patients maintained a goal heart rate (less than 110bpm) for at least 80% of the 48 hours after conversion to oral diltiazem in < 24 hours group compared to only 59% (p =0.037). The <24 hours group had more patients in heart rate goal for >85% of 48 hours after conversion to oral diltiazem compared to the >24 hours group (p=0.03). Diltiazem drips used for >24 hours had a higher percentage of ICU transfers (p = 0.035) and longer hospitalization (p = 0.001). There were no differences regarding major adverse cardiovascular events and readmission rates. Conclusions: Diltiazem drip use for <24 hours was associated with greater time spent in goal heart rate as well as a lower rate of ICU transfers and shorter hospitalization when compared to drips used > 24 hours.

Diltiazem-Induced Reversible Cardiogenic Shock in Thyroid Storm

Early recognition of underlying thyroid disease in patients presenting with new-onset tachyarrhythmia is central to management, as usual rate-control strategies can result in significant mortality and morbidity. Hyperthyroidism-induced cardiomyopathy complicated by cardiogenic shock is a life-threatening condition. Thyroid storm can lead to irreversible cardiovascular collapse and death if proper treatment is not initiated as soon as possible. In this case, we report a 44-year-old female who presented to the emergency department (ED) with the chief complaints of anxiety and palpitations. Her past medical history was significant for anxiety, but she was otherwise healthy. An electrocardiogram (ECG) in the ED demonstrated atrial fibrillation (A. fib) with rapid ventricular response (RVR) felt to be secondary to thyroid storm based on the Burch-Wartofsky point scale (BWPS), which is a quantitative diagnostic tool that uses clinical manifestation in diagnosing thyroid storm. The patient was initially managed with a continuous infusion of diltiazem to achieve rate control with a goal heart rate <115 beats per minute (bpm). Shortly after initiating the infusion, the patient developed signs and symptoms consistent with cardiogenic shock. Bedside echocardiogram revealed an estimated ejection fraction (EF) <10% with concomitant pulmonary edema. Repeat echocardiogram within 72 hours after stopping diltiazem and starting appropriate treatment for thyroid storm showed improvement of EF to 35%.

Ivabradine in Chronic Heart Failure

Heart failure (HF) is an epidemic of cardiovascular disease resulting in impaired function and worsened quality of life (QOL) of HF patients. Increased heart rate correlates with poor outcomes in these patients; therefore, its reduction may be beneficial in reducing hospitalization for worsening HF. Guideline therapy recommendation for β-blocking agents is a standard cornerstone for the treatment of HF. Despite, the dose adjustment of β-blockers for patients who cannot withstand the target dose, desired goal heart rate reduction is unfortunately not always reached. Additionally, β-blockers are contraindicated for certain patients. Ivabradine decreases the heart rate through inhibiting the cardiac pacemaker current (If) without having any influence on the sympathetic nervous system. The drug has been approved by the United States Food and Drug Administration in 2015. In 2012, ivabradine use was included in the European Society of Cardiology (ESC) guidelines for the management of HF, to be used alongside β-blockers or as a safer substitute. This short review aimed to discuss the ivabradine use in both reduced and preserved ejection fraction HF patients. Ivabradine was found to be generally tolerable and safe. Efficacy for HF patients with systolic dysfunction has been confirmed, however, in HF patients with diastolic dysfunction, it is yet to be extensively evaluated. Moreover, the role of ivabradine in HF patients with Atrial Fibrillation (AF) is currently under investigation.

Aspirin Is an Enhancing Factor for Food-Dependent Exercise-Induced Anaphylaxis in Children

To determine the effect of aspirin on challenge tests for food-dependent exercise-induced anaphylaxis (FDEIA) and food allergies with and without exercise in children who are suspected of having FDEIA on the basis of medical histories.Pediatric patients from the outpatient clinic of the department of pediatrics at Fukuoka National Hospital were recruited between 2006 and 2015. Inclusion criteria included age <18 years, no history of drug allergies, and all patients had experienced more than a single episode of anaphylaxis after exercise. Recruitment resulted in 51 children (38 boys and 13 girls, age 4–16 years, median age 11 years).Patients were instructed to discontinue antihistamines 3 to 7 days before the challenge. The exercise challenge started 30 minutes after food ingestion and was standardized to 30 minutes of aerobic exercise followed by 6 minutes of anaerobic exercise. The goal heart rate was 80% of the child’s maximum predicted heart rate. On day 1 of the study, patients underwent a causal food and exercise challenge by using an ergometer or treadmill. On day 2 of the study, patients underwent aspirin and causal food. On day 3 of the study, patients underwent aspirin, causal food, and exercise. Aspirin dosing was 10 mg/kg up to a maximum of 500 mg and was administered 30 minutes before food intake. Patient’s history and results of serum specific immunoglobulin E levels and skin prick testing determined causal food. None of the patients had reactions to the causal food by itself. Outcomes were recorded as objective symptoms, including urticaria, cough, dyspnea, edema, nausea, vomiting, and shock. The challenge was considered positive when patients exhibited any one of these symptoms. Severe reactions resulted in termination of the challenge and appropriate treatment.Out of the 51 patients, 26 had allergic reactions during at least 1 of the 3 challenge scenarios (21 boys, 6–16 years, median age of 13 years). Challenge-positive symptoms included urticaria in 21 cases (81%), cough and wheeze in 14 cases (54%), angioedema in 7 cases (27%), shock in 3 cases (12%), and nausea and vomiting in 2 cases (8%). The foods responsible for positive FDEIA reactions were shrimp in 35% (n = 9), wheat in 27% (n = 7), milk in 15% (n = 4), and peach, orange, sesame seed, onion, and fish in the remaining challenges. In the food-and-exercise-only challenges, allergic reactions occurred for 14 (54%) of the 26 patients. Two patients reacted with aspirin and causal food without exercise. In the challenge group with all 3 cofactors, all 26 patients experienced symptoms. This was statistically significant in the positive rates of the test when pretreated with and without aspirin (P < .01).Pretreatment with aspirin increased the frequency and severity of allergic reactions during challenges with causal food and exercise in pediatric patients with suspected FDEIA.In this study, the researchers demonstrate aspirin can enhance the allergic reaction in FDEIA in the pediatric population. Similar findings have previously been demonstrated in adult studies. The mechanisms for this augmented effect are thought to be twofold. First, it is felt that aspirin in conjunction with exercise increases the amount of food antigens absorbed in the intestines. Additionally, aspirin accelerates histamine release from mast cells in patients with FDEIA. Both aspirin and nonsteroidal anti-inflammatory drugs inactivate the cyclooxygenase enzyme, and nonsteroidal anti-inflammatory drugs in adults have also been shown previously to act as a third cofactor with food and exercise, triggering FDEIA. For several years, it has been recommended that aspirin should be avoided in children age <12 years because of the risk of Reye syndrome. Because of these concerns, aspirin use in US children is uncommon. It is suggested in the findings of this study that adding aspirin to pediatric exercise challenge protocols may be useful when food and exercise fail to produce symptoms and may reduce the rate of false-negative challenges. When obtaining histories from pediatric patients with FDEIA, possible medication cofactors should be explored.