Left Stellate Ganglion Block for Continuous Ventricular Arrhythmias during Percutaneous Left Ventricular Assist Device Support

Abstract

A 58-year-old man presented with chest pain and tightness and was diagnosed with a Q-wave anterior myocardial infarction. He then developed pulseless ventricular arrhythmias, which were treated with repeated direct-current shocks and intravenous amiodarone. He underwent emergency cardiac catheterization: stents were deployed in the left anterior descending coronary artery and right coronary artery, and an intra-aortic balloon pump was inserted. Severe refractory cardiogenic shock and incessant ventricular arrhythmias compelled us to place a TandemHeart percutaneous left ventricular assist device 4 hours later. The patient's hemodynamic status stabilized, but the arrhythmias persisted for 36 hours. Multiple doses of intravenous amiodarone and lidocaine and multiple external direct-current shocks were all tried, but these measures failed to terminate the life-threatening ventricular arrhythmias. We performed a pharmacologic block of the left stellate ganglion, and this resulted in a return to sinus rhythm after 1 direct-current shock. To our knowledge, this is the 1st patient with refractory ventricular arrhythmias to have been treated with TandemHeart support and left stellate ganglion block.

Evidence from experimental studies suggests that certain interventions performed on the stellate ganglion can affect the electrical activity of the heart. Pharmacologic block or ablation of the stellate ganglion can affect the sinus node rate, the atrioventricular nodal conduction, and the ventricular fibrillation threshold.^1–4 Most patients who are in hemodynamically unstable cardiogenic shock and have refractory ventricular arrhythmias cannot receive this therapy, even as a last resort, because such patients generally do not survive the resuscitation. However, with the use of percutaneous ventricular assist devices (VADs), it is possible to stabilize a patient who is in cardiogenic shock and treat malignant arrhythmias that previously would have led to death.

Herein, we describe the case of a patient who had a large myocardial infarction (MI) of the anterior wall and who was in refractory cardiogenic shock, a condition that deteriorated into life-threatening ventricular arrhythmias that persisted for 36 hours and were refractory to antiarrhythmic treatment. These arrhythmias were eventually terminated by a percutaneous pharmacologic block of the left stellate ganglion.

Case Report

A 58-year-old man with a long history of smoking experienced shortness of breath, continuous chest pain that radiated to the left arm, coughing, and an episode of vomiting. The symptoms subsided without any treatment. Four days later, he sought emergency medical assistance because the chest pain had recurred. Physical examination revealed sinus tachycardia and hypotension. An electrocardiogram showed a completed anterior-wall MI, with Q waves in leads V₁ through V₄ (Fig. 1).

Fig. 1 Electrocardiogram shows anterior-wall myocardial infarction with clear Q waves in leads V₁ through V₄.

The patient was immediately taken to the cardiac catheterization laboratory. Angiography revealed occlusion of the left anterior descending coronary artery and a critical stenosis of the distal right coronary artery. Stents were deployed in both arteries, and an intra-aortic balloon pump was inserted. Four hours later, the patient's condition deteriorated: his urine output ceased, and he remained in severe cardiogenic shock despite high doses of vasopressors. Two-dimensional echocardiography showed ventricular standstill and severe mitral regurgitation, along with an apical left ventricular thrombus. The patient developed recurrent pulseless ventricular arrhythmias that converted into sinus rhythm after a series of direct-current shocks and amiodarone administration. We then implanted a TandemHeart® (CardiacAssist Inc.; Pittsburgh, Pa) percutaneous VAD.^* Despite hemodynamic support from the TandemHeart device, ventricular arrhythmias recurred and persisted continuously for 36 hours (Fig. 2). A 300-mg bolus of amiodarone was administered, followed by an additional 150-mg bolus and continuous infusion; the total dose of amiodarone exceeded 1,500 mg. In addition, lidocaine was administered in an attempt to terminate the patient's recurrent ventricular arrhythmia, which persisted despite the use of amiodarone. A 150-mg bolus of lidocaine was followed by continuous infusion of 2 mg/min. However, combined pharmacotherapy and multiple external defibrillator shocks failed to restore sinus rhythm.

Fig. 2 Magnified electrocardiographic tracing shows fast ventricular tachycardia with changing morphology, one of the continuous arrhythmic patterns.

Because of the patient's depressed cardiac function and the apparent inefficacy of pharmacotherapy and electrical cardioversion, we decided to induce pharmacologic block of the left stellate ganglion. The patient's neck area was prepared, and ultrasonography was used to identify the left carotid artery and vein. The anterior tubercle of C6 on the left side was then palpated, and the carotid artery was retracted laterally. A 2-inch-long, 22G, short-beveled needle with an extension was then used to contact the anterior tubercle of the C6 transverse process. The needle was pulled out by about 1 mm, at which point 20 mL of 0.25% bupivacaine was gently injected in slow increments. After this procedure, the patient was defibrillated once with 200 J, and sinus rhythm was restored. Skin temperatures in both arms, as well as pupil changes, were monitored for evidence of left sympathectomy. The patient had no further sustained arrhythmias.

After the pharmacologic block was performed, telemetry showed frequent premature ventricular contractions and short 3- to 5-beat runs of nonsustained ventricular tachycardia. Three weeks after the acute episode of MI and cardiogenic shock, the patient developed an ectopic atrial tachycardia (Fig. 3). Because of a sustained heart rate of 160 beats/min and a narrow QRS complex, he underwent mapping and ablation of the ectopic tachycardia in the high crista terminalis region of the right atrium.

Fig. 3 Electrocardiogram shows ectopic atrial tachycardia.

Three weeks after the index event, 2-dimensional echocardiography still indicated severe left ventricular dysfunction. In preparation for the patient's discharge from the hospital, a dual-chamber defibrillator was implanted 6 weeks after the index event.

Discussion

A study in a canine model showed that imbalance in the sympathetic nervous signals to the heart contributes importantly to ventricular refractoriness.³ This phenomenon also plays a central role in the development of long QT syndrome and ventricular arrhythmia.⁶ The innervation of the sympathetic and parasympathetic fibers of the heart is affected by myocardial ischemia and infarction, which in turn increase sympathetic activity and the generation of ventricular arrhythmias.⁷ A study showed that left stellate ganglion block is especially effective in post-MI patients because of their increased sympathetic activity.⁸ Stellate ganglion block—a cervicothoracic sympathetic block—has been widely used as a diagnostic and therapeutic procedure for acute and chronic pain syndromes and for vascular insufficiency in the upper extremities. In addition, because left stellate ganglion block induces a significant decrease in the QT and QTc intervals,⁶ this procedure has been used to treat long QT syndrome. However, left stellate ganglion block has not been routinely used during the acute phase of refractory ventricular arrhythmia.

We inserted the TandemHeart device in this patient to stabilize his hemodynamic status, because he was in refractory cardiogenic shock despite the use of an intra-aortic balloon pump and multiple vasopressors. The TandemHeart was inserted percutaneously in the cardiac catheterization laboratory, so the patient was not at risk of the complications of a highly invasive VAD implantation procedure while in cardiogenic shock.

This case is singular in 2 ways. First, the patient, who was in cardiogenic shock and had endured ventricular arrhythmias for 36 hours, was successfully maintained with the support of a percutaneous left VAD (the TandemHeart), which provides effective hemodynamic support in patients with cardiogenic shock and severe left ventricular dysfunction.⁹ Second, this hemodynamic support enabled us to terminate the patient's malignant ventricular arrhythmias by means of left stellate ganglion block. To our knowledge, this is the 1st patient with refractory ventricular arrhythmias to have been treated with TandemHeart support and left stellate ganglion block.

Acknowledgments

Stephen N. Palmer, PhD, ELS, and Sarah J. Bronson contributed to the editing of the manuscript.