Assessment of electrocardiographic parameters in patients with electrocution injury

Arrhythmias and laboratory abnormalities after an electrical accident: a single-center, retrospective study of 333 cases

BACKGROUND

Even though electrical injuries are common in the emergency room, guidelines, consensus, and general recommendations for the management of these patients do not exist in Europe. Documented cases of delayed arrhythmias are rare and their connection with electrical injury has not been fully confirmed. We also use cardio-specific markers for the risk stratification of myocardial injury, but there is no significant study referring to their utility in this clinical situation. These reasons led us to retrospectively analyze all cases of electrical injuries over 23 years to determine the prevalence of cardiac arrhythmias (mainly malignant arrhythmias and delayed arrhythmias).

METHODS

We retrospectively searched all patients admitted to the University Hospital in Pilsen, CZ, with a diagnosis of electric injury (ICD diagnostic code T754) from 1997 to 2020. The hospital´s information system was used to research the injury; data were drawn from patient medical records.

RESULTS

We identified 333 cases of electrical injury in our hospital. Men accounted for about two-thirds, and women one-third. Children accounted for about one-third of cases. Most were low-voltage injuries (< 1000 V, 91.6%). All participants had an initial ECG, and 77.5% of patients had continuous ECG monitoring, usually lasting 24 h. Cardiac arrhythmias were noticed in 39 patients (11.7%). The most frequent arrhythmias were: ventricular fibrillation, sinus tachycardia, bradycardia and arrhythmia, atrial fibrillation, and supraventricular tachycardia. The ECG showed cardiac conduction abnormalities in 28 patients (8.1%), and ten patients (3%) had supraventricular or ventricular extrasystoles. In ten cases (3%), we found changes in ST segments and T waves on the initial ECG. Thirty-one patients (9.3%) suffered a loss of consciousness and 50 patients (15.02%) reported paresthesia. The most frequent ion disbalances were hypokalemia (18%) and hypocalcemia (3.3%). Patients with an ion disbalance had significantly more arrhythmias and newly diagnosed cardiac conduction abnormalities. Troponin levels (cTnI or hs-cTnT) were measured in 258 cases (77.48%) and found to be elevated above the 99th percentile in 19 cases (5.7%). Almost one-third of patients had burns of various degrees of seriousness, and 41 patients (12.3%) had concomitant traumatic injuries. Eleven patients underwent pre-hospital resuscitation, three died in the hospital, and another died as result of intracranial hemorrhage.

CONCLUSION

All malignant arrhythmias occurred immediately after the electrical injury, delayed life-threatening arrhythmias were not observed, and no predictive factors of malignant arrhythmias were found. While elevations of cardiac troponins were observed sporadically, they did not appear helpful for risk stratification. In patients with arrhythmias, ion disbalance may be more critical. We concluded that asymptomatic, uninjured adult and pediatric patients with normal initial ECG findings do not need continuous ECG monitoring and may be discharged home. Recommendations for high-risk patients and patients with mild ECG abnormalities at admission are less obvious.

The Importance of Frontal QRS-T Angle in Predicting the Effectiveness and Success of Thrombolytic Therapy in Patients With Acute Pulmonary Embolism

OBJECTIVE

The frontal QRS-T angle (fQRS-T) is associated with myocardial ischemia and ventricular arrhythmias. On the other hand, acute pulmonary embolism (APE) is a major risk factor for cardiac adverse events. This research aimed to determine whether the fQRS-T, a marker of ventricular heterogeneity, can be used to predict successful thrombolytic therapy in patients with APE.

METHODS

This was a retrospective observational study. Patients diagnosed with APE and hospitalized in the intensive care unit between 2020 and 2022 were included in the research. A total of 136 individuals with APEs were enrolled in this research. The patients were divided into two groups: thrombolytic-treated (n=64) and non-treated (moderate to severe risk, n=72). An ECG was conducted for each patient, and echocardiography was performed.

RESULTS

The mean age of the thrombolytic group was 58.2±17.6 years, with 35 females (55.1% of the group) and 29 males (44.9%). The non-thrombolytic group had a mean age of 63.1±16.2, with 41 females (56.5%) and 31 males (43.5%). Respiratory rate, heart rate, and fQRS-T were higher in the thrombolytic group, and oxygen saturation ratio and systolic and diastolic blood pressure were higher in the non-thrombolytic group (p=0.006, p<0.001, p=0.021; p<0.001, p=0.015, p<0.001, respectively). In the thrombolytic therapy group, comparing pre- and post-treatment ECG data revealed a statistically significant change in the fQRS-T value (p=0.019).

CONCLUSION

The fQRS-T may provide important clues for the successful treatment of APEs.

Relationship Between Atrial Fibrillation Recurrence and Frontal QRS-T Angle After Effective Cardioversion

OBJECTIVE

Maintaining sinus rhythm is important in the management of atrial fibrillation (AF). After cardioversion, there is a significant probability of AF recurrence. There is limited research on the relationship between AF recurrence and ECG parameters. This study aimed to evaluate whether the frontal plane QRS-T angle (fQRS-T), a predictor of ventricular heterogeneity, could be used to predict AF recurrence following cardioversion.

METHODS

The study was conducted as a retrospective observational study. Patients diagnosed with acute-onset AF for the first time were included in the study. All patients underwent an ECG after cardioversion, and ECG parameters were evaluated. The patients were separated into two groups based on the presence of AF recurrence during hospitalization after cardioversion. The relationship between the fQRS-T and AF recurrence was also examined.

RESULTS

A total of 162 patients, comprising 68 women (41.9%) and 94 men (58.1%) with an average age of 59.4±6.5 years, were enrolled in the research. Based on the patient monitoring device findings, patients were separated into two groups: non-recurrent AF (n=118) and recurrent AF (n=44). P-wave duration was significantly longer in the recurrence group (p=0.009). The recurrence group's mean fQRS-T was significantly higher (p<0.001). AF recurrence was substantially higher in patients with fQRS-T >90 ° compared to those with fQRS-T ≤90 ° (56.1% vs. 14.2%, p <0.001). Increased fQRS-T>93.7 ° indicated AF recurrence with 78.3% sensitivity and 83.4% specificity (AUC {area under curve}:0.748, p < 0.001). In multivariate analysis, fQRS-T was revealed to be an early indicator of recurrent AF (OR: 1.882, 95%CI: 1.358-2.881, p<0.001).

CONCLUSION

The fQRS-T, an easily determinable parameter from automatic identification ECG recordings, may be useful for predicting the early return of AF after successful cardioversion.

Risk of cardiac arrhythmias after electrical accident: a single-center study of 480 patients

Objective

Patients with electrical injury are considered to be at high risk of cardiac arrhythmias. Due to the small number of studies, there is no widely accepted guideline regarding the risk assessment and management of arrhythmic complications after electrical accident (EA). Our retrospective observational study was designed to determine the prevalence of ECG abnormalities and cardiac arrhythmias after EA, to evaluate the predictive value of cardiac biomarkers for this condition and to assess in-hospital and 30-day mortality.

Methods

Consecutive patients presenting after EA at the emergency department of our institution between 2011 and 2016 were involved in the current analysis. ECG abnormalities and arrhythmias were analyzed at admission and during ECG monitoring. Levels of cardiac troponin I, CK and CK-MB were also collected. In-hospital and 30-day mortality data were obtained from hospital records and from the national insurance database.

Results

Of the 480 patients included, 184 (38.3%) had suffered a workplace accident. The majority of patients (96.2%) had incurred a low-voltage injury (< 1000 V). One hundred and four (21.7%) patients had a transthoracic electrical injury while 13 (2.7%) patients reported loss of consciousness. The most frequent ECG disorders at admission were sinus bradycardia (< 60 bpm, n = 50, 10.4%) and sinus tachycardia (> 100 bpm, n = 21, 4.4%). Other detected arrhythmias were as follows: newly diagnosed atrial fibrillation (n = 1); frequent multifocal atrial premature complexes (n = 1); sinus arrest with atrial escape rhythm (n = 2); ventricular fibrillation terminated out of hospital (n = 1); ventricular bigeminy (n = 1); and repetitive nonsustained ventricular tachycardia (n = 1). ECG monitoring was performed in 182 (37.9%) patients for 12.7 ± 7.1 h at the ED. Except for one case with regular supraventricular tachycardia terminated via vagal maneuver and one other case with paroxysmal atrial fibrillation, no clinically relevant arrhythmias were detected during the ECG monitoring. Cardiac troponin I was measured in 354 (73.8%) cases at 4.6 ± 4.3 h after the EA and was significantly elevated only in one resuscitated patient. CK elevation was frequent, but CK-MB was under 5% in all patients. Both in-hospital and 30-day mortality were 0%.

Conclusions

Most of cardiac arrhythmias in patients presenting after EA can be diagnosed by an ECG on admission, thus routine ECG monitoring appears to be unnecessary. In our patient cohort cardiac troponin I and CK-MB were not useful in risk assessment after EA. Late-onset malignant arrhythmias were not observed.