Angiographic analysis of the anatomic relation of coronary arteries to mitral and tricuspid annulus and implications for radiofrequency ablation

Long-term risk of right coronary artery injury after catheter ablation of cavotricuspid isthmus-dependent flutter

BACKGROUND

Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)-dependent atrial flutter requires ablation of the tricuspid annulus overlying the right coronary artery (RCA). Although it is considered safe, reports of acute and subacute RCA injury in human and animal studies raise the possibility of late RCA stenosis.

OBJECTIVE

The objective of this study was to compare the incidence and severity of angiographic RCA stenoses in patients who have undergone CTI RFA with a control group to assess the long-term risk of RCA damage.

METHODS

A 2-center retrospective case-cohort study was performed including all patients from 2002 to 2018 undergoing atrial fibrillation (AF) with CTI ablation (CTI + AF) or AF ablation alone with subsequent coronary angiography (CAG). The AF alone group served as controls because of anticipated similarity of baseline characteristics. Coronary arteries that are anatomically remote to the CTI were examined as prespecified falsification end points. CAG was scored by a blinded observer.

RESULTS

There were 156 patients who underwent pulmonary vein isolation with subsequent CAG (CTI + AF, n = 81; AF alone, n = 75) with no difference in baseline characteristics including age, sex, comorbidities, and medications. Mean time from ablation to CAG was similar (CTI + AF, 5.0 ± 3.7 years; AF alone, 5.4 ± 3.9 years; P = .5). The mid and distal RCA showed no difference in the average number of angiographic stenoses or lesion severity. In regression analysis, CTI ablation was not a predictor of RCA stenosis severity (P = .6). There was no difference in coronary disease at sites remote to the CTI ablation (P = NS for all).

CONCLUSION

There was no observed relationship between CTI RFA and the number or severity of angiographically apparent RCA stenoses in long-term follow-up.

When too much closeness harms: circumflex artery injury during mitral valve surgery

Occlusion of the left coronary circumflex artery (LCX) during surgical procedures of the mitral valve is an infrequent but potentially life-threatening complication (1-3). Due to its close anatomical relationship to the posterior mitral valve annulus, there is a relevant risk of causing a stenosis or an occlusion of the left circumflex artery, especially by surgical annular sutures. The perioperative clinical course is heterogeneous, ranging from-initially-asymptomatic or solely electrocardiographic abnormalities to cardiogenic shock. Both severely impaired ventricular contractility or malignant arrhythmia may potentially lead to a weaning failure from cardiopulmonary bypass (CPB) and eventually result in chronic heart failure with persistently reduced ejection fraction. Possible therapeutic strategies include the immediate reopening of causal sutures, aortocoronary bypass grafting or percutaneous coronary intervention (PCI), yet PCI seems to be the preferred method at present.

Coronary artery dissection following radiofrequency ablation for atrial fibrillation: Case report and review of the literature

Coronary artery injury following catheter ablation for cardiac arrhythmias is very rare. We present a case of left circumflex (LCx) coronary artery dissection causing inferoposterior ST-elevation myocardial infarction following radiofrequency (RF) ablation for atrial fibrillation (AF) in a 39-year-old male with no cardiovascular risk factors. This was confirmed on coronary angiography and intracoronary vascular ultrasound (IVUS). The likely etiology is thermal injury during RF ablation for AF, due to the close proximity of the left atrial appendage and left pulmonary veins to the LCx. He was successfully treated with primary percutaneous coronary intervention with good outcome. This is, to our knowledge, the first reported case of proven acute coronary dissection secondary to RF ablation for AF reported in the literature, and highlights the importance of considering this as a mechanism for coronary occlusion in these patients.

Coronary artery occlusion following low-power catheter ablation

Myocardial infarction (MI) is an unusual but potentially serious complication of catheter ablation procedures. This case describes the occurrence of acute myocardial infarction following low-power ablation in a young patient and highlights the importance of maintaining high index of suspicion following catheter ablation irrespective of the ablation power used. A 22-year-old patient had low-power ablation of the right posteroseptal accessory pathway in the ostium of the coronary sinus on account of persistently symptomatic WPW syndrome with orthodromic re-entrant tachycardia. Two hours after the procedure, she developed moderately severe chest pain. Electrocardiogram showed ST elevation in the inferior leads. Coronary angiography showed 100% stenosis of the right coronary artery just beyond the posterior descending artery. She failed balloon angioplasty and a drug eluting stent was placed in the posterolateral branch of the right coronary artery. The symptoms resolved and follow up echocardiogram showed normal left ventricular systolic and diastolic functions with no regional wall motion abnormality. This case demonstrates the occurrence of MI following low-power catheter ablation. Patients should be monitored for this complication irrespective of the ablation power used.

An unusual treatment of coronary injury following radiofrequency ablation in a 5-year-old child: Systemic steroid usage

Radiofrequency catheter ablation (RFCA) procedure is performed for many tachyarrhythmias. We performed successful RFCA in a 5-year-old child for supraventricular tachyarrhythmia and Wolff-Parkinson-White syndrome. Acute circumflex artery (CxA) occlusion occurred due to RFCA. After percutaneous balloon angioplasty was performed into the CxA, the patient was treated with systemic steroid to resolve myocardial edema. To the best of our knowledge, systemic steroid was used first time for acute coronary artery injury related myocardial ischemia.

Coronary artery injury related to catheter ablation of cardiac arrhythmias: A systematic review

INTRODUCTION

Catheter ablation (CA) has emerged as the preferred modality of treatment for many cardiac arrhythmias. Anatomical sites of ablation are often located in close proximity to coronary arteries. However, the incidence of CA-related coronary injury has not been well studied. We sought to systematically evaluate all cases of CA-related coronary injuries.

METHODS AND RESULTS

A PubMed search was conducted from inception until May 1, 2017 using the keywords "coronary artery" and "ablation." We identified 2817 published articles of which 43 articles met our inclusion criteria representing 61 cases of coronary artery injury attributed to CA procedures from 1992 to 2017. Posteroseptal accessory pathway ablation was associated with the highest incidence of coronary injury (35.6% of cases), followed by cavotricuspid isthmus-dependent flutter (19.3%). The right coronary artery was the site of injury in over two-thirds of all reported cases. Coronary injury was detected intraprocedurally in about half of the cases (43.1%), whereas it was a delayed presentation in the other half. Coronary intervention was performed in a third of all cases (32.7%). There were a total of three deaths attributed to coronary artery injury.

CONCLUSIONS

Most (91.8%) coronary injuries are a result of anatomic proximity to the site of ablation. Awareness of the relation between coronary artery course and anatomical site of ablation could prevent myocardial damage and improve procedural safety.

Circumflex coronary artery injury after mitral valve surgery: A report of four cases and comprehensive review of the literature

As the LCx is closely related to the mitral valve annulus, it is susceptible to perioperative injury. Various underlying mechanisms, predisposing factors, and therapeutic strategies have been suggested but disagreement exists. Using a MeSH terms-based PubMed search, 44 cases of mitral valve surgery-related LCx injury were detected, including our 4 cases. We provide a comprehensive review of current knowledge regarding mitral valve surgery-related left circumflex coronary artery (LCx) injury. Preoperative coronary angiography was performed in 55% (n = 24). Coronary abnormalities were present in 11% (n = 5). Coronary dominance was reported in 73% (n = 32), predominantly showing left (69%, n = 22) or balanced (19%, n = 6) circulations. Right coronary dominance was present in 12% (n = 4). Ischemia was detected in the perioperative or early postoperative phase in 86% (n = 30). Delayed symptoms were present in 14% (n = 5). Echocardiography demonstrated new regional wall motion abnormalities in 80% (n = 24), but was negative in 20% (n = 6) despite coronary compromise. Electrocardiography showed myocardial ischemia in 97% (n = 34), including regional ST-segment elevations in 68% (n = 23). Primary treatment was surgical in 42% (n = 15) and percutaneous in 58% (n = 21), reporting success ratios of 87% (n = 13) and 81% (n = 17), respectively. We confirm an augmented risk of mitral valve surgery-related LCx injury in balanced or left-dominant coronary circulations. Preoperative knowledge of coronary anatomy does not preclude LCx injury. An anomalous LCx arising from the right coronary cusp was identified as a possible specific high-risk entity. Electrocardiographic monitoring and intraoperative echocardiography remain paramount to ensure a timely diagnosis and treatment. © 2016 Wiley Periodicals, Inc.

Efficacy of ablation at the anteroseptal line for the treatment of perimitral flutter

Background

Left atrial flutter following atrial fibrillation (AF) ablation is increasingly common and difficult to treat. We evaluated the safety and efficacy of ablation of the anteroseptal line connecting the right superior pulmonary vein (RSPV) to the anteroseptal mitral annulus (MA) for the treatment of perimitral flutter (PMF).

Methods

We systematically studied patients who were previously treated with AF ablation and who presented to the electrophysiology laboratory with atrial tachyarrhythmias between January 2000 and July 2010. The diagnosis of PMF was confirmed by activation mapping and/or entrainment. After re-isolation of any recovered pulmonary vein, a linear radiofrequency (RF) ablation was performed on the line that connected the RSPV to the anteroseptal MA. In this analysis, we included only patients who were treated with an anteroseptal line for their PMF.

Results

Ablation was performed at the anteroseptal line in 27 PMF patients (63±13 years; 9 women) who had undergone prior ablation for paroxysmal (n=3) or persistent (n=24) AF, using electroanatomic activation mapping (70% CARTO, 30% NavX). The anteroseptal ablation line was effective in 22/27 (81.5%) patients in the acute-care setting. Termination of AF to sinus rhythm occurred in 15/22 (68.2%) patients, and 7/22 (31.8%) patients׳ AF converted to another right or left atrial flutter. At the 6-month follow-up, 20% of patients demonstrated recurrent left atrial tachyarrhythmia. Only one patient required repeat ablation, and the remaining patients׳ condition was controlled with antiarrhythmic medications. No major procedural complications or heart block occurred.

Conclusion

Ablation at the left atrial anteroseptal line is safe and efficacious for the treatment of PMF. Unlike ablation at the traditional mitral isthmus line, ablation at the left atrial anteroseptal line does not require ablation in the coronary sinus.

Atrial flutter ablation and risk of right coronary artery injury

Radiofrequency ablation (RFA) of atrial flutter (AFL) is a commonly performed procedure with low risk of complications. Several case reports and animal studies cautioned about the risk of right coronary artery (RCA) injury following AFL ablation. This risk is due to the anatomic proximity of the RCA to the cavo-tricuspid isthmus where ablation is performed. We present a case report that demonstrates postmortem evidence of RCA injury following RFA of AFL.

Catheter ablation of accessory pathways near the coronary sinus: value of defining coronary arterial anatomy

BACKGROUND

Accessory pathways can lie near or within the coronary sinus (CS). Radiofrequency catheter ablation of accessory pathways is a well-established treatment option, but this procedure can cause damage to adjacent coronary arteries.

OBJECTIVE

The purpose of this study was to evaluate the anatomic relationship between the coronary arteries and the CS.

METHODS

Retrospective data of patients who underwent catheter ablation of supraventricular tachycardia between June 2011 and August 2013 was reviewed. In addition, detailed analysis of coronary computed tomographic angiography (CTA) data from 50 patients was performed.

RESULTS

Between June 2011 and August 2013, 427 patients underwent catheter ablation of supraventricular tachycardia, of whom 105 (age 28 ± 17 years, 60% male) had accessory pathway-mediated tachycardia. Of these, 23 patients had accessory pathways near the CS, and 60% (N = 14) underwent concurrent coronary angiography. In 4 patients, the posterolateral (inferolateral) branch (PLA) of the right coronary artery was in close proximity to the CS, and 2 patients (18%) had stenosis of the PLA at the site of ablation. On CTA at their closest proximity, the PLA was 1.9 ± 1.3 mm and the left circumflex artery (LCx) was 2.0 ± 0.8 mm from the body of the CS, in right and left coronary artery-dominant patients, respectively. CS ostium and PLA were 3.6 ± 1.9 mm apart. In left-dominant patients, LCx and CS ostium were 3.8 ± 1.2 mm apart.

CONCLUSION

The PLA and LCx are in close proximity to the anteroinferior aspect of the CS ostium and proximal CS. The relationship of the CS and coronary arteries should be evaluated before ablation at these sites.

Iatrogenic right coronary artery stenosis resulting from surgical tricuspid valve replacement: case report and review of the literature

Iatrogenic injury to the right coronary artery (RCA) is a rare complication of tricuspid valve surgery. We herein describe the first-ever report of RCA injury related to tricuspid valve replacement surgery. A 38-year-old man with recurrent tricuspid endocarditis underwent redo tricuspid valve replacement by means of a minimally invasive right thoracotomy with a 32-mm St. Jude bioprosthetic valve. His post-operative course was complicated by pulseless ventricular tachycardia requiring CPR and defibrillation. Cardiac catheterization revealed a "kinked" stenotic distal RCA. The lesion was noted to be flow limiting by fractional flow reserve and was treated with two everolimus-eluting stents. The RCA runs in the atrioventricular groove and is susceptible to injury especially in the region of the posterior leaflet of the tricuspid valve, where the relationship of the tricuspid annulus to the RCA is most intimate. Repair of surgically induced coronary stenosis can be accomplished with percutaneous intervention.

A review of mitral isthmus ablation

Mitral isthmus ablation forms part of the electrophysiologist’s armoury in the catheter ablation treatment of atrial fibrillation. It is well recognised however, that mitral isthmus ablation is technically challenging and incomplete ablation may be pro-arrhythmic, leading some to question its role. This article first reviews the evidence for the use of adjunctive mitral isthmus ablation and its association with the development of macroreentrant perimitral flutter. It then describes the practical techniques of mitral isthmus ablation, with particular emphasis on the assessment of bi-directional mitral isthmus block. The anatomy of the mitral isthmus is also discussed in order to understand the possible obstacles to successful ablation. Finally, novel techniques which may facilitate mitral isthmus ablation are reviewed.

Proximity of right coronary artery to cavotricuspid isthmus as determined by computed tomography

BACKGROUND

Radiofrequency ablation of atrial flutter is a commonly performed procedure. Ablation success depends upon complete transmural atrial tissue injury to achieve bidirectional cavotricuspid isthmus (CTI) block. Transmural ablation increases risk of injury to the adjacent right coronary artery (RCA). Distance between the RCA and the endocardium within the CTI area is not well described. We aimed to perform in vivo measurements of the distance between the CTI area and adjacent RCA.

METHODS

Thirty-three consecutive patients underwent electrocardiogram-gated contrast-enhanced computed tomography. CTI area was divided into nine segments based on three common catheter locations (paraseptal, central, and lateral or 5, 6, and 7 o'clock) and ventricular to atrial ablation line.

RESULTS

Mean age was 64 ± 11 years and 97% of the participants were male. Paraseptal, central, and lateral measurements at the tricuspid annulus ridge showed endocardial to RCA distance 9 ± 3, 6 ± 2, and 5 ± 3 mm, respectively (range 2-17 mm). Corresponding measurements for the ventricular side were 5 ± 3, 4 ± 2, and 4 ± 2 mm and atrial side measurements were 3 ± 2, 3 ± 2, and 3 ± 3 mm. Distance was ≤2 mm in 14% of segments on the ventricular side and 39% of segments on the atrial side. Paired t-test showed significant difference (P < 0.001) between tricuspid annulus ridge measurements and adjacent atrial or ventricular measurements.

CONCLUSIONS

Distance between endocardium and RCA lumen is reduced in areas adjacent to the tricuspid annulus ridge.

Larger coronary sinus diameter predicts the need for epicardial delivery during mitral isthmus ablation

AIMS

Mitral isthmus ablation is technically challenging, often requiring both endocardial and epicardial coronary sinus (CS) ablation. Blood flow in the CS and circumflex artery may act as a 'heat sink' and reduce the efficacy of radiofrequency ablation. This study investigates how the CS and circumflex artery diameters affect mitral isthmus ablation.

METHODS AND RESULTS

Thirty-five patients underwent ablation for atrial fibrillation. Irrigated-tip catheters were used during mitral isthmus ablation with the following settings: endocardial surface (maximum power: 40-50 W at the annular end of line; maximum temperature: 48°C); CS (maximum power: 25-30 W; maximum temperature: 48°C). The absence of block after 10 min of endocardial ablation led to CS ablation for up to 5 min. If there was still no block, further ablation was at the discretion of the physician. Coronary angiography and CS venography were performed and analysed with quantitative coronary angiography. Mitral isthmus block was achieved in 31 patients (89%). Twenty-three patients (74%) required CS ablation to achieve block. These patients were found to have significantly larger CS diameters (6.5 ± 1.2 vs. 5.4 ± 0.5 mm, P< 0.02). Coronary sinus diameter >59 mm predicted the need for CS ablation (specificity: 100%; sensitivity: 78%). Coronary sinus diameter correlated significantly with total mitral isthmus ablation time (r = 0.52, P < 0.003) and CS ablation time (r = 0.59, P < 0.0005), whereas circumflex diameter did not.

CONCLUSION

Larger-diameter CS is associated with a need for CS ablation during mitral isthmus ablation. Coronary sinus but not circumflex diameter was significantly correlated with total and CS ablation time, supporting the hypothesis that the CS but not the circumflex artery acts as a heat sink.