Navigating Tortuous Coronary Sinus Anatomy Using a Bipolar Lead

Case History
An 80-year-old male patient presented to his primary care physician with reoccurring panic attacks and dyspnea; the panic attacks and symptoms were worse at night. He was unsuccessfully treated with anti-anxiety medications, and visited the emergency room several weeks later with dyspnea and angina. The patient exhibited classic New York Heart Association Class III symptoms of heart failure; he was unable to walk around his house without becoming fatigued, and was experiencing angina about once a week. The patient had undergone coronary bypass surgery several years prior to this event, and he had a history of coronary artery disease, hypertension, hyperlipidemia, ischemic cardiomyopathy, and a left ventricle ejection fraction (EF) of 20 percent. He also had a history of sick sinus syndrome for which a pacemaker had been implanted. The pacemaker provided atrial pacing and ventricular sensing, with the intrinsic signal showing a left bundle branch block (LBBB). His symptoms developed while on a good medical therapy of aspirin, carvedilol, rosuvastatin calcium, valsartan, furosemide, and clopidogrel.

Diagnosis

The patient had an electrocardiogram that revealed an atrially paced rhythm and a wide LBBB morphology, with a QRS of 176 (Figure 1). The patient was appropriately diagnosed as suffering from heart failure, rather than an anxiety disorder, and he was directed to meet with a heart failure specialist.
In August 2007, a left ventricular angiography was conducted. The RFA was cannulated using the Seldinger technique, and a 5 French sheath was inserted into the artery over a guidewire. The angiography confirmed the ischemic cardiomyopathy diagnosis and showed three-vessel coronary artery disease, abnormal LV function, and ejection fraction of 10%.

Therapy Decision
The 80-year-old patient expressed a main goal of improving quality of life and did not want to pursue therapies aimed at prevention of sudden cardiac arrest. He declined the suggestion of a cardiac resynchronization therapy defibrillator (CRT-D) device because of its defibrillation capacity. He did, however, agree to life-improving therapy, so the decision was made to implant a Frontier^® II model 5586 cardiac resynchronization pacemaker (CRT-P) (St. Jude Medical, St. Paul, MN) for biventricular pacing. The patient’s existing pacemaker would be removed, and, assuming the existing RA and RV lead measurements remained stable, an LV (coronary sinus) lead would be added to complete the resynchronization vector.

Choosing and Implanting the Lead
In November 2007, the patient underwent the procedure to implant the Frontier II CRT-P. To gain access, the CPS Direct® SL outer guide catheter (St. Jude Medical, extra wide curve, model 410115, 47 cm) was used via the standard subclavian stick approach. The coronary sinus (CS) was cannulated via standard technique. The guide catheter was inserted into the right ventricle, then retracted while counter-clockwise torque was applied. The preformed curve of the guide catheter allowed easy access to the coronary sinus. After occlusive CS venography, the only viable target was a single lateral branch, midway up the coronary sinus. There was no visible secondary branch and an atretic posterior lateral branch, so the single lateral branch was the only acceptable vessel. Unfortunately, this vessel had a greater than 90-degree take-off angle and, immediately after this transition, demonstrated tortuosity that resembled the Greek letter omega (Figure 2).

Because of the tortuosity of this vein, a unipolar lead was first considered. Typically, unipolar leads track around tortuous veins better than bipolar leads, due to the fact that unipolar leads have a single electrode, while bipolar leads have two electrodes. However, unipolar leads limit therapy delivery to unipolar pacing, with no ability to make changes in pacing settings if adjustments are needed after initial surgery. To ensure optimal therapy delivery and to meet future pacing needs, the QuickSite^® XL 1058T bipolar lead (St. Jude Medical) was selected. Its wider separation of bipoles and larger curve at the distal end were designed to provide excellent maneuverability (Figure 3).
To implant the lead, the standard “Floppy Firm” guidewire (model 4078G, St. Jude Medical) was advanced to well beyond the tortuosity. Using an over-the-wire approach — after some initial difficulty — the lead was maneuvered through the 90-degree turn and advanced smoothly past the proximal challenges. It was placed in the true, left lateral mid-ventricular position — an extremely secure position because the proximal tortuosity now worked as an advantage, stabilizing the lead and passively anchoring it into place (Figure 4).

About the Lead
The QuickSite XL lead was the best choice for this case since it has a polyurethane body that provides good pushability, a steerable, deflectable tip, and a large s-shaped curve to provide stability and maneuverability. The proximal polyurethane section and cable/coil conductors offer exceptional push and torque, while the flexible distal silicone portion is designed for improved maneuverability in tortuous anatomy. The lead also has had excellent implant success rates and stability; in clinical studies, the QuickSite family of LV leads was shown to have an implant success rate of 97% and a dislodgement rate of only 1%.¹

Follow-Up and Results
The patient was seen at one-week, two-week and two-month follow-up appointments, and has had an excellent clinical outcome. He reported feeling better after two weeks, and, although he reported some fatigue, it was primarily due to typical deconditioning observed in most Class III patients. The patient reported that his only regret was not doing the procedure earlier.
Despite the deconditioning, the patient’s heart failure symptoms decreased from Class III, borderline Class IV symptoms, to NYHA Class I–II symptoms. He has had resolution of his angina and no further episodes of anxiety or panic attacks. His QRS narrowed to 155 ms, and he demonstrated excellent ECG characteristics of textbook lead placement with good LV capture (Figure 5). Biventricular pacing morphology revealed an initial negative vector in lead I and a positive vector in V1. Additional confirmation was performed. ECGs were recorded with RV only, LV only, and biventricular pacing. Biventricular pacing was a fusion of RV and LV only morphologies.

Conclusion
The QuickSite XL 1058T lead effectively navigated tortuous anatomy for a successful implantation in the coronary sinus. The addition of the coronary sinus lead allowed for biventricular pacing that improved the QoL as well as the heart failure symptoms of this patient. The availability of a bipolar lead with enough flexibility and maneuverability to navigate the tortuous coronary sinus made it possible to use — instead of a unipolar lead — during the lead placement. The availability of this flexible bipolar lead option provided the patient optimal therapy for his clinical condition. In summary, I believe the QuickSite lead family would be an appropriate choice for physicians uncertain about the ability of bipolar LV leads to maneuver through difficult anatomy. The stability, low dislodgement rate, s-shaped curve and steerable tip make the QuickSite lead a good choice for optimal, stable LV lead placement.

Reference

1. QuickSite^® Lead Family data represents data pooled on the QuickSite Models 1056K and QuickSite Model 1056T from the RHYTHM ICD/QuickSite Model 1056K lead study (163 patients) and the RHYTHM ICD/QuickSite Model 1056T lead study (144 patients) [QuickSite Models 1056K and 1056T lead user’s manual]/© 2005 St. Jude Medical. Reprinted with permission from EP Lab Digest 2008;3(8):34,37.

Editor’s Note: This article underwent peer review by one or more members of EP Lab Digest’s editorial board.