Electrocardiographic abnormalities in patients with diphtheria: a prospective study

Electrocardiographic Changes in COVID-19 Patients: A Hospital-based Descriptive Study

Background

Coronavirus disease-2019 (COVID-19) infection is a multisystem disease not restricted to the lungs. It has a negative impact on the cardiovascular system by causing myocardial damage, vascular inflammation, plaque instability, and myocardial infarction. The presence of myocardial injury is a poor prognostic sign. Electrocardiogram (ECG), a simple bedside diagnostic test with high prognostic value, can be employed to assess early cardiovascular involvement in such patients. Various abnormalities in ECG like ST-T changes, arrhythmia, and conduction defects have been reported in COVID-19. We aimed to find out the ECG abnormalities of COVID-19 patients.

Methods

We performed a cross-sectional, hospital-based descriptive study among 315 COVID-19 in-patients who underwent ECG recording on admission. Patients’ clinical profiles were noted from their records, and the ECG abnormalities were studied.

Results

Among the abnormal ECGs 255 (81%), rhythm abnormalities were seen in 9 patients (2.9%), rate abnormalities in 115 patients (36.5%), and prolonged PR interval in 2.9%. Short QRS complex was seen in 8.3%. QT interval was prolonged in 8.3% of the patients. Significant changes in the ST and T segments (42.9%) were observed. In logistic regression analysis, ischemic changes in ECG were associated with systemic hypertension and respiratory failure.

Conclusion

In our study, COVID-19 patients had ischemic changes, rate, rhythm abnormalities, and conduction defects in their ECG. With this ongoing pandemic of COVID-19 and limited health resources, ECG—a simple bedside noninvasive tool is highly beneficial and helps in the early diagnosis and management of cardiac injury.

How to cite this article

Kaliyaperumal D, Bhargavi K, Ramaraju K, Nair KS, Ramalingam S, Alagesan M. Electrocardiographic Changes in COVID-19 Patients: A Hospital-based Descriptive Study. Indian J Crit Care Med 2022;26(1):43–48.

Diphtheria

Diphtheria is a potentially fatal infection mostly caused by toxigenic Corynebacterium diphtheriae strains and occasionally by toxigenic C. ulcerans and C. pseudotuberculosis strains. Diphtheria is generally an acute respiratory infection, characterized by the formation of a pseudomembrane in the throat, but cutaneous infections are possible. Systemic effects, such as myocarditis and neuropathy, which are associated with increased fatality risk, are due to diphtheria toxin, an exotoxin produced by the pathogen that inhibits protein synthesis and causes cell death. Clinical diagnosis is confirmed by the isolation and identification of the causative Corynebacterium spp., usually by bacterial culture followed by enzymatic and toxin detection tests. Diphtheria can be treated with the timely administration of diphtheria antitoxin and antimicrobial therapy. Although effective vaccines are available, this disease has the potential to re-emerge in countries where the recommended vaccination programmes are not sustained, and increasing proportions of adults are becoming susceptible to diphtheria. Thousands of diphtheria cases are still reported annually from several countries in Asia and Africa, along with many outbreaks. Changes in the epidemiology of diphtheria have been reported worldwide. The prevalence of toxigenic Corynebacterium spp. highlights the need for proper clinical and epidemiological investigations to quickly identify and treat affected individuals, along with public health measures to prevent and contain the spread of this disease.

Severe diphtheria with neurologic and myocardial involvement in a Swedish patient: a case report

Background

Diphtheria is caused by Corynebacterium diphtheriae. Although waning in incidence diphtheria can cause severe disease as in this rare Swedish case with several complications.

Case presentation

A 55-year old male presented to the emergency room with severe respiratory symptoms and greyish membranes in the airways, which turned positive for C. diphtheriae. He was put on ventilator support and remained hospitalized for three months. During care he developed myocarditis and severe neurological disease and he was also co-infected with tuberculosis. The patient was discharged with a favorable outcome.

Conclusions

Diphtheria should be suspected in patients with life-threatening pneumonia especially if the patient has a history of travelling. Our patient was not treated with diphtheria anti-toxin (DAT) which may have contributed to the severity of the disease.

Historical assessment of diphtheritic myocarditis from a hospital in northeastern Thailand

Background: Although there have been many descriptive studies of diphtheria from resource limited countries, descriptions of the natural history of diphtheritic myocarditis in patients from these countries are scarce.

Objective: To present the natural history of diphtheritic myocarditis from a hospital in northeastern Thailand.

Methods: The clinical features of 38 patients with diphtheria admitted to the Khon Kaen University Hospital in northeastern Thailand between 1983 and 1996 were reviewed.

Results: Of the 38 cases of diphtheria, 10 progressed to diphtheritic myocarditis (26%). Electrocardiographic findings of the 10 patients with myocarditis were myocardial and conduction abnormalities. The presence of a clinically severe (toxic) type (P < 0.001) or a swollen neck (bull neck) (P = 0.001) was a predictor of the occurrence of myocarditis. Five (50%) of the 10 patients with myocarditis had conduction abnormalities (third-degree atrioventricular block 3, left bundle branch block 1, and right bundle branch block 1). Four patients with severe symptomatic bradyarrhythmia (third-degree atrioventricular block 3, and left bundle branch block 1) received ventricular pacing, and 3 patients died after this pacing. Echocardiographic abnormalities of left ventricular dilatation and myocardial hypertrophy were found in all 5 patients with conduction abnormalities. All 6 of 7 survivors of diphtheritic myocarditis had normal 12-lead electrocardiographic results at 1-month follow-up. A patient who was the survivor of third-degree AV block had an electrocardiographic finding of flat T waves, and with a complete echocardiographic normalization of left ventricular dilatation and myocardial hypertrophy.

Conclusion: The present study confirms that increasing diphtheria immunization coverage in the population remains the most important strategy for the control of diphtheria. In resource limited countries, clinical findings, electrocardiography, and sometimes where available, echocardiography are helpful in assessing the severity of diphtheritic myocarditis, decision making of acute management, and predicting fatal outcome.

Electrocardiographic abnormalities in patients with novel H1N1 influenza virus infection

The cardiac effects imposed by the novel H1N1 influenza strain have not been elucidated until now. Electrocardiographic (ECG) abnormalities were evaluated in a series of 50 patients with confirmed novel H1N1 influenza infection. Epidemiologic and clinical characteristics, laboratory correlations, and the effect ECG abnormalities may exert on disease outcomes were prospectively studied. Of the 50 patients, 14 (28%) exhibited ECG changes on admission. Nine patients presented with T-wave inversions, while ST-segment depression was observed on the electrocardiograms of 6 patients. The presence of ECG changes did not correlate with age, gender, co-morbidities, the laboratory profiles of the patients, or the coexistence of lower respiratory tract involvement. None of the patients exhibited alterations in cardiac-specific biochemistry or cardiac ultrasonography. All ECG changes were transient and reversed during disease regression. Two patients with ECG changes and 1 with normal ECG findings required intensive care, the former 2 eventually dying. Among the remainder, the duration of hospitalization did not exhibit a significant difference between the 2 groups, although there was a trend toward fewer days of hospitalization in the patients with ECG changes. In conclusion, ECG abnormalities are frequently encountered during novel H1N1 influenza infection, but their presence does not indicate a direct pathogen effect to the myocardium; these alterations may necessitate admission in the first place but are transient and not correlated with preexisting patient characteristics or with outcomes.

Prognostic significance of electrocardiographic abnormalities in diphtheritic myocarditis after hospital discharge: a long-term follow-up study

OBJECTIVE

We aimed to investigate the long-term cardiac mortality and the relationship between cardiac mortality and electrocardiographic abnormalities in patients with diphtheritic myocarditis who survived after hospital discharge.

MATERIALS AND METHODS

Between 1991 and 1996, 32 patients (all males, mean age 21.00 +/- 3.77 years) surviving diphtheritic myocarditis were included in the study and they were followed up for an average of 16.3 months (range 10.3-26.8 months) after hospital discharge. Clinical evaluation, ECG, and echocardiography were performed on admission, daily while in hospital and at the time of discharge. ECG changes were permanent during the follow-up period. The causes of death of the patients during follow-up period were inferred from the death records of the patients and talking to the people witnessing cardiac arrest.

RESULTS

We observed that the patients with left bundle branch block (LBBB) and T wave inversion at hospital discharge had lower survival rates than that of the patients without these ECG changes in the long term. Although univariate Cox regression analysis identified LBBB (P = 0.001) and T wave inversion (P = 0.014) as the predictors of survival, only LBBB was an independent predictor of survival in multivariate Cox regression analysis. Adjusted hazard ratio was calculated as 13.67 for LBBB (P = 0.001; CI = 2.81-66.28).

CONCLUSION

Diphtheritic myocarditis does not only demonstrate a malignant clinical course during acute phase of the disease, but also during the long-term follow-up period, especially in patients with LBBB and T wave inversion. Besides, T wave inversion and LBBB can help us to predict survival rate of the patients in long term. Moreover, LBBB is an independent predictor of long-term survival in diphtheritic myocarditis.

Clinical features and predictors of diphtheritic cardiomyopathy in Vietnamese children

BACKGROUND

Despite the availability of antitoxin and antibiotics, the mortality rate for diphtheria remains high, mostly because of cardiac complications.

METHODS

During 1 year, 154 Vietnamese children with diphtheria admitted to a referral hospital were studied prospectively with clinical examination, including a simple pseudomembrane score, 12-lead and 24-hour electrocardiography, measurement of serum cardiac enzyme levels, and estimation of troponin T levels.

RESULTS

Thirteen children had diphtheritic cardiomyopathy on admission, and 19 developed it subsequently. Twelve children (8%) died. The combination of pseudomembrane score of >2 and bull neck predicted the development of diphtheritic cardiomyopathy, with a positive predictive value of 83% and a negative predictive value of 93%. Administration of 24-hour electrocardiography on admission improved the ability to predict diphtheritic cardiomyopathy by 57%. Fatal outcome was best predicted by the combination of myocarditis on admission and a pseudomembrane score of >2. Of the cardiac enzyme levels measured, an elevated aspartate aminotransferase level was the best predictor. The presence of troponin T identified additional children with subclinical cardiac damage.

CONCLUSIONS

The development of diphtheritic cardiomyopathy can be predicted by means of simple measures.