Pacing site in pacemaker dependency: is right ventricular septal lead position the answer?

Abstract

The right ventricular apex has been the traditional site for lead placement in patients with atrioventricular block. Pacing at the right ventricular apex may have long-term deleterious effects on left ventricular (LV) function, promoting heart failure and increasing mortality. Pacing at the right ventricular septum has been proposed to minimize deterioration in LV function. Although experimental data suggest that septal pacing protects LV function, clinical studies have provided conflicting results. A recent large study in patients with heart block did not show a protective effect with septal pacing. Other pacing approaches are becoming increasingly relevant; however, prediction of what method should be employed in which patient is not currently possible. Other factors such as baseline LV function and associated co-morbidities impact LV function, irrespective of pacing site. Continued monitoring of cardiac function post-implant is therefore critical to ongoing care. An algorithm for managing patients with atrioventricular block is proposed.

Keywords::

• alternate site pacing
• atrioventricular block
• cardiac resynchronization therapy
• heart failure
• left ventricular function
• right ventricular apical pacing
• right ventricular septal pacing

Financial & competing interests disclosure

G Kaye has received lecture fees from Medtronic and Pfizer and grants from Medtronic supporting the ProtectPace study and a study into the optimal imaging to determine pacing lead position. G Kaye also lectures at educational meetings run by Sorin Inc. but does not receive financial remuneration for this. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Right ventricular apical pacing for long-term bradycardia support is an effective and life-saving therapy.

• Experimental and clinical observations show that long-term right ventricular pacing can result in a decline in left ventricular function, so-called pacing-induced cardiomyopathy, increasing risk of heart failure and mortality.

• Concern that right ventricular apical pacing should be avoided has fuelled exploration of non-apical pacing alternatives. The right ventricular septum and outflow tract have been the most studied positions. Inconsistent effects on left ventricular function have been found and research does not support a change of clinical practice away from right ventricular apical pacing in all patients.

• Lead position is not the sole determinant of heart failure development in paced patients. Co-morbidities and left ventricular function at pacing implantation influence left ventricular deterioration.

• Patients who require pacing should have individualized consideration and management of other risk factors, not least to offset potential deleterious long-term effects of right ventricular lead position.

• Although it is likely that use of sophisticated approaches such as cardiac resynchronization therapy and left ventricular pacing modalities will increase, a single easily implantable pacemaker lead remains the ideal for many patients. Right ventricular pacing still fulfils these requirements for patients with well-preserved left ventricular function and controlled co-morbidities.

• Serial monitoring of left ventricular function following device implantation and management of co-morbidities and heart failure are important for all paced patients.