Acute STEMI Due to Severe Triple-Vessel Spasm After IV Adenosine Injection During Cryo-Balloon Isolation.

Adenosine IV is commonly used after pulmonary vein isolation to check for dormant electrical conduction. Herein, we present the case of a 60-year-old patient who exhibited marked hypotension, conduction abnormalities, and ST-segment elevation after routine adenosine injection. Coronary angiography revealed diffuse coronary spasm that was successfully treated with intracoronary nitroglycerin. (Level of Difficulty: Intermediate.).

History Of Presentation

The patient underwent uneventful pulmonary vein isolation (PVI) ablation with a second-generation cryo-balloon catheter under moderate sedation in a high-volume atrial fibrillation (AF) center with monitoring via intracardiac echocardiography and invasive arterial pressure during the procedure. At the end of ablation, adenosine 12 mg was injected to check for dormant conduction in the pulmonary veins because ablation of these reconnection sites has been shown to decrease the recurrence of AF.1, 2, 3, 4 As the second dose of adenosine was injected to check for conduction in the left inferior pulmonary vein, self-limited complete heart block resulted, followed by rather unusual (prolonged severe) hypotension. Marked diffuse ST-segment elevation ensued, then left bundle branch block, followed by complete heart block.

Learning Objectives

To recognize acute coronary spasm caused by IV adenosine.

To reconsider the utility of using high-dose adenosine in confirmation of pulmonary vein isolation, given the potential for serious life-threatening complications.

Past Medical History

A 60-year-old man with a medical history significant for allergic rhinitis, hyperlipidemia, paroxysmal atrial fibrillation, cardiomyopathy, and obesity was referred to the cardiac electrophysiologist to explore treatment for his paroxysmal atrial fibrillation. The patient’s paroxysmal atrial fibrillation had been difficult to medically manage, resulting in tachycardia-induced cardiomyopathy. The patient’s medications included losartan potassium, loratadine, atorvastatin calcium, folic acid, rivaroxaban, fluticasone propionate, and metoprolol succinate. The patient’s beta-blocker was withheld for 2 days prior to ablation. Physical examination revealed an irregular cardiac rhythm, a heart rate of 90 beats/min, and blood pressure of 132/88 mm Hg. The patient reported breathlessness on exertion and 2 recent episodes of blurry vision; he denied chest pain, chest pressure, palpitations, dizziness, lightheadedness, or loss of consciousness. The patient did not have any pre-existing coronary artery disease. After a discussion of the risks and benefits of various treatment options, the patient elected to proceed with cryo-balloon PVI.

Differential Diagnosis

The patient presented with ST-segment elevation myocardial infarction toward the end of his PVI ablation and after IV adenosine was administered. He experienced an acute deterioration of his hemodynamic status. The differential diagnosis included vasospasm from cryoablation, allergic reaction to IV contrast material, or idiosyncratic reaction to IV adenosine infusion. Vasospasm from cryoablation was excluded because the timing of the symptoms correlated with the administration of adenosine, which was almost 20 minutes after completion of the cryoablation therapies. The patient had no history of allergic reactions to IV contrast material. He underwent cardiac catheterization the same day and the subsequent day and had no reaction to the contrast material.

Investigations

Immediate coronary angiography was performed via the arterial line already in situ (Figures 1 and 2). Severe diffuse coronary artery spasm was observed in both the right and left coronary arteries.

Figure 1

Initial Image Left Coronary Artery System

Severe diffuse coronary vasospasm of left coronary artery system (left main, left anterior descending, left circumflex) immediately after adenosine injection. Decapolar electrophysiology catheter shown in right ventricle for temporary pacing.

Figure 2

Initial Image Right Coronary Artery System

Severe diffuse coronary vasospasm of right coronary artery system immediately after adenosine injection. Decapolar electrophysiology catheter shown in right ventricle for temporary pacing.

Management (Medical/Interventions)

Temporary RV pacing was initiated at 600 ms, and immediate coronary angiography was performed via the arterial line already in situ (Figures 1 and 2). Severe diffuse coronary artery spasms were observed in both the right and left coronary arteries. Intracoronary nitroglycerin progressively relieved the spasm and improved flow over the next 30 minutes, with resolution of the complete heart block and ST-segment elevation (Figures 3 and 4). The patient was transferred to the coronary care unit and given maintenance IV nitroglycerin drip. His troponin I peaked at 15 ng/mL, and a repeated coronary angiogram the following day showed no significant residual epicardial coronary artery abnormality (Figures 5 and 6).

Figure 3

Improvement Left Coronary Artery System

Image obtained after administration of intracoronary nitroglycerin injection, showing improvement in left coronary artery system.

Figure 4

Improvement Right Coronary Artery System

Image obtained after administration of intracoronary nitroglycerin injection, showing improvement in right coronary artery system.

Figure 5

Repeated Coronary Angiogram Left Coronary Artery System

Follow-up coronary angiogram 24 hours after ablation shows resolution of coronary spasms and return of normal flow to left coronary artery system.

Figure 6

Repeated Coronary Angiogram Right Coronary Artery System

Follow-up coronary angiogram 24 hours after ablation shows resolution of coronary spasms and return of normal flow to right coronary artery system.

Discussion

Adenosine IV exerts its antiarrhythmic effects on the sinus node, AV node, and atrial tissue owing to its effects on potassium conductance and antiadrenergic actions, resulting in slowed AV node conduction and block as well as sinus slowing and arrest. It is a safe pharmacological agent used during noninvasive stress testing, is occasionally suspected as a cause of chest pain, electrocardiographic changes of ST-segment elevation, coronary spasm, heart block,, and rarely myocardial infarction. We present a clearly documented case of such an effect, occurring unusually in the context of PVI, the standard protocols of which frequently call for multiple high-dose central venous or intracardiac adenosine injections to check for dormant conduction.1, 2, 3 The use of IV adenosine to check for dormant conduction in PVI ablation is a common practice, although there are conflicting data to support the utility of further ablating for such conductions.

Follow-Up

The patient returned the following day for repeated coronary angiography, which showed no significant coronary artery disease (Figures 5 and 6).

Conclusions

Given the rare but life-threatening potential complications of IV adenosine and the common use of it for checking for latent PVI conduction, there should be increased awareness, prompt recognition, and adequate intervention protocols set in place. We also advance that repeated use of IV adenosine and similar-class medications should be deemed contraindicated in patients noted to have this paradoxical response.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.