Bandar Al-Ghamdi*, Azam Shafquat and Yaseen Mallawi
Heart Centre, King Faisal Specialist Hospital and Research Centre (KFSH&RC), College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
Received: 14 May, 2016; Accepted: 24 May, 2016; Published: 25 May, 2016
Bandar Al-Ghamdi, MD, Heart Centre, King Faisal Specialist Hospital and Research Centre, MBC-16, PO Box 3354, Riyadh, 11211 Saudi Arabia, Tel: +966-011-464-7272; Ext: 31584; Fax: +966-011-442-7791; E-mail:
Al-Ghamdi B, Shafquat A, Mallawi Y (2016) Cardiac Contractility Modulation Device and Subcutaneous Implantable Cardioverter Defibrillator Combination: A New Hope for Heart Failure Patients with Low Ejection Fraction and Narrow QRS Complex. J Cardiovasc Med Cardiol 3(1): 018-022. DOI: 10.17352/2455-2976.000024
© 2016 Al-Ghamdi B, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
S-ICD; CCM; Heart failure; Sudden death
Background: Heart failure (HF) is a common cardiovascular disease with high rates of morbidity and mortality despite advances in medical and device-related management. Cardiac Contractility Modulation (CCM) is a promising therapy in HF patients with narrow QRS complex and CCM devices are approved and available for clinical use in Europe. On the other hand, there has recently been an increased interest in subcutaneous implantable cardioverter defibrillators (S-ICD) in HF patients with low ejection fraction. S-ICDs obviate the vascular and lead complications associated with conventional ICDs. There are limited data about the combination of CCM and S-ICD in management of HF patients.
Methods: We reviewed literature about current use of CCM and S-ICD as well as data on their use in combination. We are also reporting our first case with this combination.
Results: The combination of the two devices is feasible, seems to be safe, and is without significant interaction between the two systems.
Conclusion: CCM and S-ICD combination in patients with HF, functional class II-IV, low ejection fraction, and narrow QRS is an attractive approach as it avoids numerous leads inside the body. However, more studies are needed to prove that this approach is effective and has good clinical outcome.
Heart failure is a common cardiovascular disease with a high morbidity and mortality despite advances in medical and device-related management. Cardiac resynchronization therapy (CRT) which is also known as biventricular pacing has proven to be an effective treatment in heart failure [1-6]. However, CRT is generally recommended for patients in sinus rhythm and prolonged QRS complex (≥ 120 ms) with left bundle branch block (LBBB), or a QRS complex width of ≥ 150 ms in the absence of LBBB . On the other hand, only 30-40% of all heart failure patients show such a prolonged QRS complex [7,8] and therefore the 60-70% of patients who have a normal QRS complex cannot be treated with CRT. Furthermore, around 30% of the patients eligible for CRT treatment do not respond to CRT [7,8].
Heart failure patients with low ejection fraction and narrow QRS complexes benefit from Cardiac Contractility Modulation (CCM) however they are also at risk for sudden cardiac death (SCD) . Guidelines for prevention of sudden cardiac death are well described and include the use of implantable cardiac defibrillators (ICDs). In heart failure patients who do not require pacing or CRT but are candidates for CCM, the use of subcutaneous implantable cardioverter defibrillator devices (S-ICD) is a proven and attractive option especially compared to transvenous ICD systems. CCM paired with S-ICD provides the preferred treatment options while minimizing intravascular leads .
The aim of this review is to have an overview of these two technologies and its combination, and to give an example of a successful combination.
Cardiac contractility modulation (CCM)
CCM is a cardiac implantable electronic device (CIED) that enhances ventricular contractile strength of the failing myocardium, with delivering a high voltage non-excitatory electrical impulses during the absolute refractory period state of the cardiac muscle cells independently of synchrony of myocardial contraction [10-13]. These signals do not initiate a new contraction or affect activation sequence .
The CCM signals are relatively high-voltage electrical impulses delivered to the myocardium 30–40 ms after detection of local myocardial activation during the absolute refractory period (Figure 1). A bi-phasic square wave pulse is the most common waveform utilized. The CCM pulses can be described by parameters of phase duration, delay from activation and signal amplitude. Studies of the mechanisms underlying the acute and prolonged effects of CCM signals have focused on their impact on action potentials, peak intracellular calcium, calcium loading of the sarcoplasmic reticulum and gene expression [10,15,16].