Role of Coronary Angiography Before Radiofrequency Ablation in Patients Presenting With Paroxysmal Supraventricular Tachycardia

Investigation of clinical significance of ST-segment depression during paroxysmal supraventricular tachycardia

INTRODUCTION

There are great differences in ST-segment depression during PSVT episodes. The aim of this study is to investigate the clinical significance of ST segment depression during PSVT.

METHODS

The study enrolled 333 consecutive patients who were diagnosed with PSVT by electrophysiological test from Jan 1, 2021 to July 31, 2022. The range, magnitude and morphology of ST-segment depression were described. The correlation between ST-segment depression and symptoms of chest tightness, chest pain or hypotension, the correlation between ST-segment depression and coronary stenosis, and the possible influencing factors were analyzed. In addition, the diagnostic efficacy of ST-segment depression for AVRT was determined.

RESULTS

ST-segment depression was present in 85% of patients, in 70% of which the depression range was more than six leads. The magnitude of the depression was more significant in precordial leads (P < 0.001). ST-segment depression of >1 mm in limb leads and precordial leads was found in 36.0% and 49.8% of the patients, respectively, while >3 mm was found in 2.4% and 9.6%, respectively. The morphology of ST-segment depression in limb leads was different from that in precordial leads (P < 0.001). Downsloping ST-segment depression was more common in limb leads (limb vs. precordial: 40.5% vs. 12.6%), whereas upsloping depression was more common in precordial leads (limb vs. precordial: 3.0% vs. 23.1%). Correlation analysis showed that ST-segment depression was not correlated with symptoms of chest tightness and pain, nor was it correlated with coronary artery stenosis. The most important influencing factor is the type of PSVT, especially affecting the morphology of depression in limb leads (OR = 10.27 [5.93-17.79], P < 0.001). The sensitivity and specificity of downsloping ST-segment depression in limb leads for diagnosis of AVRT were 75.5% and 76.7%.

CONCLUSION

ST-segment depression is a common ECG change during PSVT episodes, and it's not associated with severe coronary stenosis. The type of PSVT has a significant effect on the manifestation of ST-segment depression. The downslope morphology of ST-segment depression in limb leads is helpful in differentiating AVRT from AVNRT.

ST-segment depression in atrioventricular nodal reentrant tachycardia: Important finding or just an artifact?

BACKGROUND

The ST segment is component of the QRS-T complex located between the QRS and the T wave. ST segment changes during tachycardia with narrow QRS mainly takes the form of ST segment depression. This phenomenon is often observed in young healthy people for whom an ischemic background is unlikely.

MATERIALS AND METHODS

The study included 104 patients (71 women and 33 men) with paroxysmal narrow QRS complex tachycardia. In all patients electrophysiological study was performed and the diagnosis of atrioventricular nodal reentrant tachycardia was established. The arrhythmogenic substrate was then eliminated successfully by subsequent ablation using radiofrequency energy which confirmed the diagnosis, all patients had measured QRS components - QR, RS and RJ during the tachycardia and during the sinusrhythm. All of the measurements were done in lead V5.

RESULTS

The difference RJ-QR during tachycardia and sinus rhythm correlated negatively with tachycardia cycle length (R = 0.356, P = .001), first slowly, then rapidly reaching the cycle value of about 300 ms, then it decreases, stabilizing at the cycle level of about 270. By separating the RJ-QR in tachycardia and in the sinus rhythm from the tachycardia cycle, we can see that the correlation described in this point is largely due to the correlation between the heart rate and RJ-QR length in tachycardia.

CONCLUSIONS

In patients with atrioventricular nodal reentrant tachycardia, there is a significant ST-segment depression during tachycardia episodes and the degree of this change is related to tachycardia cycle length. The most probable explanation of the ST-segment depression is the overlap of the QRS complex on the preceded T wave. This phenomenon is also influenced by some intrinsic properties of the individual electrocardiogram. It is possible to rule out ischemic origin of the presented ST segment change.

Underuse of Catheter Ablation as First-Line Therapy for Supraventricular Tachycardia

Background

Catheter ablation (CA) is a safe, effective, cost‐effective technique and may be considered a first‐line strategy for the treatment of symptomatic supraventricular tachycardias (SVT). Despite the high prospect of cure and the recommendations of international guidelines in considering CA as a first‐line treatment strategy, the average time between diagnosis and the procedure may be long. The present study aims to evaluate predictors related to non‐referral for CA as first‐line treatment in patients with SVT.

Methods and Results

The model was derived from a retrospective cohort of patients with SVT or ventricular pre‐excitation referred for CA in a tertiary center. Clinical and demographical features were used as independent variables and non‐referral for CA as first‐line treatment the dependent variable in a stepwise logistic regression analysis. Among 20 clinical‐demographic variables from 350 patients, 10 were included in initial logistic regression analysis: age, women, presence of pre‐excitation on ECG, palpitation, dyspnea and chest discomfort, number of antiarrhythmic drugs before ablation, number of concomitant symptoms, symptoms’ duration and evaluations in the emergency room due to SVT. After multivariable adjusted analysis, age (odds ratio [OR], 1.2; 95% CI 1.01–1.32; P=0.04), chest discomfort during supraventricular tachycardia (OR, 2.7; CI 1.6–4.7; P<0.001) and number of antiarrhythmic drugs before ablation (OR, 1.8; CI 1.4–2.3; P<0.001) showed a positive independent association for non‐referral for CA as SVT first‐line treatment.

Conclusions

The independent predictors of non‐referral for CA as first‐line treatment in our logistic regression analysis indicate the existence of biases in the decision‐making process in the referral process of patients who would benefit the most from catheter ablation. They very likely suggest a skewed medical decision‐making process leading to catheter ablation underuse.

Assessment of the Utility of Ordering a Troponin in Low- and Intermediate-Risk Patients Presenting to the Emergency Department with Supraventricular Tachycardia: A Retrospective Chart Review

BACKGROUND

A troponin assay is commonly sent for patients presenting to emergency departments (EDs) with supraventricular tachycardia (SVT). Multiple studies suggest that elevated troponin levels do not predict coronary artery disease in these patients. Patients with elevated troponins are more likely to have additional cardiac testing, which can lead to increased health care costs and unnecessary invasive procedures.

OBJECTIVE

Our objective was to evaluate low- to intermediate-risk patients (HEART [history, electrocardiography, age, risk factors and troponin] Score 1-6) presenting to the ED with SVT. Our hypothesis was that an elevated troponin would not predict major adverse cardiac events (MACE), but would be associated with increased hospital admission rates and lengths of stay.

METHODS

This was a retrospective cohort study of adult patients who presented with SVT to a large, urban, academic hospital ED over 4 years who had a troponin result. A total of 46 patients were included in the study.

RESULTS

Patients with a positive troponin (>0.05 ng/mL) had a hospital admission rate of 86% versus 21% for patients with negative troponin (p = 0.006); rate of cardiology consult of 86% versus 21% (p < 0.001); and a mean total length of stay of 4157 min versus 1347 min (p = 0.04). At 3 months, none of the patients with a positive troponin had an MACE, death from any cause, or positive results of cardiac testing.

CONCLUSIONS

Patients with a positive troponin result had significantly more admissions, cardiology consults, and longer hospital stays. These patients did not have an increased prevalence of MACE.

Review article: The utility of troponin and other investigations in patients presenting to the emergency department with supraventricular tachycardia

Patients with supraventricular tachycardia commonly present to the ED. There is a lack of consensus regarding assessment of these patients. Our aim was to determine the utility of troponin and four other investigations (full blood examination, electrolyte levels, thyroid function tests and chest X-rays) commonly requested for these patients. MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (January 1992-March 2017) were searched for randomised controlled trials and observational studies (of sample size greater than 10). Our search strategy yielded no randomised controlled trials and seven observational studies with significant statistical heterogeneity among selected studies (I² 87.3%, P < 0.001). Included studies investigated a total of 1155 patients. All studies reported on the utility of troponin testing in this patient population. The pooled proportion of patients investigated with troponin was 0.66 (95% confidence interval 0.44-0.88). The pooled proportion of positive troponin tests was 0.32 (95% confidence interval 0.23-0.41). Only one study reported on the utility of the remaining four investigations with abnormal results as follows: thyroid stimulating hormone 14%, haemoglobin 6%, white cell count 19% and chest X-ray 22%. Investigations are commonly requested for patients presenting with supraventricular tachycardia. Troponin testing is commonly performed with a high proportion of positive findings although these results did not appear to be associated with major adverse cardiac events. Heterogeneity among studies and low levels of evidence precluded conclusions on full blood examinations, electrolyte levels, thyroid testing and utility of chest X-rays in this patient population.

Two in one is better than one plus one: comparison of adverse events between combining electrophysiological examination and coronary angiography versus performing them consecutively

PURPOSE

In some patients, both an electrophysiological examination (EPS) and a coronary angiography (CA) are necessary. It might be preferable to choose a combined approach of EPS and CA versus performing them consecutively. The purpose of this study is to evaluate the type and rate of adverse events between both approaches.

METHODS

Patients were eligible if they underwent a CA and an EPS in a combined approach or in a time interval of at most 2 months. In all patients, clinical adverse events were recorded.

RESULTS

A total of 1184 patients were included. CA and EPS were performed in a combined procedure (comb) in 492 patients, whereas they were performed consecutively in 692 patients (cons). The acute major complication rate was 0.67%, showing no differences between both groups. In the comb 6.9% and in the cons 6.6% of vascular complications were observed (p = 0.20). The rates of AV fistula and hematoma needing transfusion showed a significantly higher rate in the cons group (p = 0.018 and p = 0.045, respectively). In a multivariate logistic regression analysis, age was a significant predictor for groin complications. After propensity matching, AV fistula occurred significantly more often in the cons group (p = 0.002).

CONCLUSION

Overall, serious adverse events were rare and there were no differences between the combined approach of EPS and CA and the consecutive approach; however, the occurrence of AV fistula and groin hematoma needing transfusion occurred significantly less in the combined procedure group. Therefore, a combined approach is preferable to a consecutive one.

Evaluation of left ventricular longitudinal deformation in patients with and without ST segment depression during supraventricular tachycardia

BACKGROUND

The cumulative effect of repeated demand ischemia on left ventricular (LV) systolic function has been previously demonstrated. We evaluated the longitudinal deformation of LV myocardial fibers at systole and diastole using two-dimensional speckle-tracking echocardiography (2DSTE) in patients with and without ST-segment depression during supraventricular tachycardia.

METHODS

We recruited 104 consecutive patients, who were admitted to our hospital for the ablation of atrioventricular nodal reentrant tachycardia or atrioventricular reentrant tachycardia. The patients were thereafter evaluated by transthoracic echocardiography and 2DSTE, and longitudinal systolic strain and strain rate as well as early and late diastolic strain rates were measured.

RESULTS

We found no statistically significant differences in longitudinal systolic strain and strain rate as well as in early and late diastolic strain rates between the two study groups.

CONCLUSIONS

The longitudinal deformation properties of LV muscle fibers were not different between patients with and without ST-segment depression during supraventricular tachycardia. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:343-349, 2017.

Usefulness of laboratory and radiological investigations in the management of supraventricular tachycardia

OBJECTIVE

Although ED patients presenting with supraventricular tachycardia (SVT) are commonly investigated, the value of these investigations has been questioned. We aimed to determine the frequency and utility of investigations in patients with SVT.

METHODS

We undertook an explicit retrospective medical record audit of patients with SVT who presented to a single ED (January 2004 to June 2014). Data on demographics, presenting complaints, investigations and outcomes were extracted. The outcomes were nature and utility of investigations.

RESULTS

A total of 633 patients were enrolled (mean [SD] age 55.4 [17.7] years, 62% female). Laboratory investigations were common: electrolytes (83.7% of patients), full blood count (81.2%), magnesium (57.5%), calcium (39.3%) and thyroid function (30.3%). These investigations revealed many mildly abnormal results but resulted in electrolyte supplementation in only 19 patients: eight with mild hypokalaemia (potassium 3.0-3.5 mmol/L) and 11 with mild hypomagnesia (magnesium 0.49-1.1 mmol/L). Troponin was ordered for 302 (47.7%) patients, many of whom had no history or risk factors for cardiac disease, or ischaemic symptoms associated with their SVT. The troponin was normal, mildly and moderately elevated in 65.2, 24.5 and 10.2% of cases, respectively. Only seven (1.1%) patients were diagnosed with acute myocardial ischemia. Although 190 (30.0%) patients had a chest X-ray (CXR), it was normal in 78.4% of cases. All CXR abnormalities were incidental and not relevant to the immediate ED management.

CONCLUSION

Patients with uncomplicated SVT are over-investigated. Guidelines for ED SVT investigation are recommended. Further research is recommended to determine the indications for each investigation in the setting of SVT.

The retrograde P-wave theory: explaining ST segment depression in supraventricular tachycardia by retrograde AV node conduction

BACKGROUND

Pseudo ischemic ST segment changes during supraventricular tachycardia (SVT) are not yet fully understood. Our aim was to determine whether venticulo-atrial (VA) conduction during SVT may be a possible mechanism for ST depression (STd) in SVT.

METHODS

Patients undergoing SVT ablation (2010-2012) were analyzed (n = 72).Typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) were included. Those with STd were compared to those without STd. VA interval length, tachycardia cycle length (TCL), and retrograde P-wave activation during SVT were assessed. Retrograde P waves arriving simultaneously with the ST segment (PWST) during SVT were considered, whenever an atrial electrogram (measured from the high right atrium) was "on time" with the ST segment.

RESULTS

Patients with STd during SVT presented longer VA intervals than those without STd (VA 100 ± 37 ms vs VA 69 ± 22 ms; P = 0.006). No differences in TCL were observed (TCL 333 ± 35 ms vs TCL 360 ± 22 ms; P = 0.1). PWST was observed in 38.5% of patients with AVNRT and STd versus 0% in those without STd. The TCL was similar in both groups (355 ± 25 ms vs 334 ± 18 ms; P = 0.1). In patients with AVRT and STd, PWST was present in 81% of cases versus 0% in those without STd. The TCL was also similar (330 ± 29 ms vs 346 ± 17 ms; P = 0.1).

CONCLUSIONS

STd during SVT is observed at long VA intervals when the retrograde P wave matches the ST segment, without dependence on the TCL. This suggests that STd is not necessarily rate dependent but a result of a fusion between the ST segment and the P wave.

Cardiac troponin I elevation with supraventricular tachycardia: two case reports and review of the literature

Background

Although cardiac troponin I gives excellent accuracy in the identification of myocardial necrosis, it can also be elevated in a series of diseases other than acute coronary syndromes.

Case presentation

We present two cases of Chinese patients with a high serum troponin I level after an acute episode of paroxysmal supraventricular tachycardia with normal coronary arteries via angiography.

Conclusion

Abnormal troponin elevations can be seen in patients presenting with paroxysmal supraventricular tachycardia and angiographically-normal coronary arteries. Caution is advised with the use of invasive assessments such as coronary angiography in the differential diagnosis of patients with paroxysmal supraventricular tachycardia and elevated troponin levels.

Relationship of myocardial ischemia and injury to coronary artery disease in patients with supraventricular tachycardia

Increase of serum troponin I and ST-segment depression are objective markers of myocardial ischemia/injury. Abnormalities of the 2 indicators have been associated with supraventricular tachycardia (SVT) but their relevance for diagnosing acute coronary syndrome and the presence of coronary artery disease (CAD) in this setting have not been clarified. Therefore, we sought to evaluate the frequency of CAD based on increased troponin I and ST-segment depression during SVT. During a 5-year period, 104 patients were admitted with a diagnosis of SVT, 80 of whom had troponin I testing, and 70 of these patients could be assessed for ST-segment changes. Thirty-seven patients (48%) had increased troponin I (mean 1.54 +/- 2.7 ng/dl, normal <or=0.07 ng/dl) and 46 patients (57%) had ST-segment depression >or=1.0 mm. There were no significant differences in baseline characteristics and clinical presentation of patients with and without troponin I increase or ST-segment depression. There was no difference in the diagnosis of CAD by noninvasive or invasive testing in patients with and without increased troponin I. More patients with than without ST-segment depression had evidence of CAD (22% vs none, p = 0.01), but after adjusting for covariates, ST-segment depression was not a significant predictor of CAD. In conclusion, increased troponin I and ST-segment depression are not significant markers of acute coronary syndrome in patients with SVT.