Cardiac troponin T and myocardial injury during routine cardiac catheterisation in children

Pediatric defibrillation shocks alone do not cause heart damage in a porcine model

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AEDs utilize specific low energy pediatric modes to reduce myocardial damage.

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This study applied various shocks in sinus rhythm without cardiac instrumentation.

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Isolated clinically relevant shock sequences do not result in myocardial damage.

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Typical variations in pediatric shocks did not affect safety and efficacy.

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These results may inform future pediatric resuscitation guidelines.

Aim

Automated external defibrillators (AEDs) use various shock protocols with different characteristics when deployed in pediatric mode. The aim of this study is to assess and compare the safety and efficacy of different AED pediatric protocols using novel experimental approaches.

Methods

Two defibrillation protocols (A and B) were assessed across two studies: Protocol A: escalating (50–75–90 J) defibrillation waveform with higher voltage, shorter duration and equal phase durations. Protocol B; non-escalating (50–50–50 J) defibrillation waveform with lower voltage, longer duration and unequal phase durations.

Experiment 1: Isolated shock damage was assessed following shocks to 12 anesthetized pigs. Animals were randomized into two groups, receiving three shocks from Protocol A (50–75–90 J) or B (50–50–50 J). Cardiac function, cardiac troponin I (cTnI), creatine phosphokinase (CPK) and histopathology were analyzed. Experiment 2: Defibrillation safety and efficacy were assessed through shock success, ROSC, ST-segment deviation and contractility following 16 randomized shocks from protocol A or B delivered to 10 anesthetized pigs in VF.

Results

Experiment 1: No clinically meaningful difference in cTnI, CPK, ST-segment deviation, ejection fraction or histopathological damage was observed following defibrillation with either protocol. No difference was observed between protocols at any timepoint. Experiment 2: all defibrillation types demonstrated shock success and ROSC ≥ 97.5%. Post-ROSC contractility was similar between protocols.

Conclusions

There is no evidence that administration of clinically relevant shock sequences, without experimental confounders, result in significant myocardial damage in this model of pediatric resuscitation. Typical variations in AED pediatric mode settings do not affect defibrillation safety and efficacy.

Can troponin T levels be useful in the diagnosis of rheumatic carditis?

Objective:

Acute rheumatic fever (ARF) is an endemic disease observed in children of developing countries. The purpose of this study was to test if it was possible to identify myocardial involvement in cases with rheumatic carditis by the measurement of serum cardiac TnT.

Methods:

30 patients diagnosed as ARF underwent echocardiography and their cardiac troponin T (cTnT) serum levels were measured. Patients were divided into group 1: Arthritis alone, group 2: carditis, and group 3 carditis with congestive heart failure (CHF).

Results:

cTnT serum levels were normal in all except one patient with in group 3. Two patients in carditis (group 2) and three patients in CHF (group 3) had dilation in left ventricular end diastolic diameter.

Conclusions:

Normal cTnT levels in our patient group suggests that inflammation rather than myocardial necrosis is predominant in ARF carditis.

Cardiac troponin T in children with acute rheumatic carditis

The existence of cardiac damage in active rheumatic carditis patients is unknown, especially in those without pericarditis. The aim of this study was to determine cardiac myocyte damage using cardiac troponin T (cTnT) measurements in active rheumatic carditis. The levels of creatine kinase MB isoenzyme (CK-MB), cTnT, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), cardiothoracic ratio (CTR), and fractional shortening (FS) were compared using Mann-Whitney U test between 28 patients with active rheumatic carditis and 32 controls (healthy children). Association of cTnT levels with ESR, CRP, and CTR was evaluated with Spearman correlation analysis. ESR, CRP, cTnT levels, and CTR were statistically higher in the patients than in the controls. There were no differences between the groups for CK-MB levels and FS. No relationships were found between cTnT levels and ESR, CRP, and CTR in the patient group. The results of the study suggest that when cTnT levels are within non-pathological range, there is no serious cardiac damage; however, statistically significant increases in cTnT levels may indicate minor damages in patients with active carditis due to acute rheumatic fever.

Myocardial involvement in the hemodynamic abnormalities associated with acute rheumatic fever

BACKGROUND AND AIM

Rheumatic fever is still a common cause of acquired heart disease in children and young adult in many developing countries. The aim was to investigate the role of myocardial involvement in the hemodynamic changes in patients with acute rheumatic fever using cardiac troponin assay and echocardiography.

DESIGN

A prospective cohort study was designed.

PATIENTS AND METHODS

Thirty-four children with acute rheumatic fever, 20 with carditis, and 14 without carditis. Level of cardiac troponin T (cTnT) and echocardiographic measurement of left ventricular function were the main outcome measure.

RESULTS

The level of cardiac troponin in children with carditis was 0.051 ± 0.01 ng/dL, and it was 0.039 ± 0.02 ng/dL in those without carditis. The difference is not significant. In addition, there was no significant difference between the children with carditis and those without carditis regarding left ventricular ejection and shortening fractions.

CONCLUSION

There are no significant echocardiographic measurements abnormalities or cTnT levels elevation suggesting clinically relevant hemodynamic abnormalities due to myocardial involvement during acute rheumatic fever.

The ontogeny of biochemical markers of cardiac dysfunction

PURPOSE OF REVIEW

Biochemical markers are available to detect cardiac involvement in many pediatric disease states and should be considered.

RECENT FINDINGS

Analyses of three markers are readily available in clinical laboratories for improved diagnosis.

SUMMARY

Increased workload of the heart has been associated with the release of biochemical markers (natriuretic peptides and cardiac enzymes) that indicate that a new genetic program has been activated and maladaptation is occurring in the atria, ventricles, or both. This review summarizes those that have been identified in fetal and pediatric practice. The expression of such markers is traced from early embryonic development to fetal life, to the neonate, to childhood, and then to adult life.