The first Life Healthcare ‘His-bundle’ cardiac pacemaker procedure, a relatively new procedure for some patients with irregular heart beat or arrhythmia was recently performed by Dr Vinod Thomas, an electrophysiologist and cardiologist at Life Vincent Pallotti Hospital.
The successful procedure was performed on a 75-year-old patient, who initially was treated for type 2 diabetes mellitus and chronic renal impairment by specialist geriatrician, Dr Faheema Parker, based at Life Vincent Pallotti Hospital. The patient was referred to Dr Thomas after being diagnosed with severe heart failure and an inability to tolerate beta-blockers. The patient’s range of motion was limited to sitting upright.
An ECG confirmed a left ventricular function of only 15% with left ventricular dyssynchrony, and sinus tachycardia with left bundle branch block (QRS width = 140ms). Results from the tests showed that the patient met the criteria for a cardiac resynchronisation device (CRT).
The CRT pacing device is a complex pacemaker with three leads positioned in the right atrium, right ventricle and over the left ventricular wall respectively; the idea being to use precise electrical impulses to synchronise the timing of both right and left ventricles to improve overall heart function. In this intervention all three leads bypass the heart’s fundamental conduction system, allowing direct adjustment to the pacing of each beat of the patient’s heart.
In this case the left ventricular lead (coronary sinus lead) of the CRT device proved, technically, to be extremely difficult to position. The usual option after an aborted left ventricular lead placement is to refer the patient to a cardio-thoracic surgeon for an epicardial lead placement; however, the patient was too frail to tolerate such cardiac surgery.
Engaging the heart’s intrinsic conduction system
“Due to the limited options available to the patient, ‘His-bundle pacing’ was decided upon and performed. ‘His-bundle’ pacing is a relatively new technology within the cardiologist’s armamentarium in the battle against heart failure. Unlike conventional pacing, ‘His-bundle’ pacing engages the heart’s intrinsic conduction system to activate the ventricles; if done properly it can be used to narrow an intraventricular conduction delay (wide QRS) to within normal limits thereby enabling the ventricles to contract more synchronously, which improves overall heart function,” said Dr Thomas.
The ‘His-bundle’ pacing procedure caused a decrease in left bundle branch size from 140ms to 94ms (a 32% improvement), and by day two after the procedure the patient’s symptoms improved to the point where she was mobile again, with the assistance of a walker. “The concept of ‘His-bundle’ pacing is novel and innovative and, at this point, the expertise for its application is limited in South Africa. The hope is that this technique has the potential to replace pacing for slow heart rates, helping with sick sinus syndrome and/or atrioventricular heart block,” said Dr Vinod.
Beneficial where increased pacing is anticipated
‘His-bundle’ pacing is proving to be particularly beneficial in patients with heart failure and a slow heart rate, where pacing is anticipated to be greater than 20-30%. It is also important to note that more evidence is required before the procedure can routinely replace more complex resynchronisation pacing devices. However, it is currently considered a reasonable alternative in a failed or aborted coronary sinus left ventricular lead placement, as was the case with Dr Thomas’s patient.
Dr Vinod also gave his thanks to the catheterisation laboratory, 24-hour Heart Centre team and allied staff members who worked efficiently and harmoniously to ensure the patient’s safety and comfort. He said, “Considering that it was the first case of its kind done at Life Vincent Pallotti Hospital and within the Life Healthcare Group, the procedure was handled exceptionally well.”