The main objective is to investigate mechanical alternans and MTWA in patients with heart failure caused by coronary artery disease to demonstrate a possible correlation between these two phenomena.

In patients with severe heart failure and aortic valve disease mechanical alternans or pulsus alternans (a condition in which there is a beat-to-beat oscillation in the strength of cardiac muscle at a constant heart rate) is observed.

The mechanisms linking mechanical to electrophysiological dysfunction in heart failure are still under investigation, but impaired calcium cycling is the most striking abnormality of failing myocytes, and is most responsible for contractile dysfunction. Yet it remains unclear how this influences susceptibility to arrhythmias.

The MTWA is suggested as a risk marker to identify high risk patients for potential VTEs but the underlying mechanism is not completely understood. The aim of this study is to investigate this in a clinical setting by measuring LV parameters using a PV loop conductance catheter and generate TWA recording simultaneously to demonstrate a possible correlation between these two phenomena in patients with ischemic heart failure and find out if MTWA could turn into a more valuable risk factor.

Our hypothesis is that alternating changes in LV filling explains the electrocardiogenesis of TWA by changing the position of the heart relative to the body surface electrodes in an alternating way.

Inclusion Criteria:

• Patients with heart failure caused by coronary artery disease
• Indication for left ventricular radiofrequency (LV RF) ablation
• LVEF ≤ 35% measured by echocardiogram or MRI

Exclusion Criteria:

• hemodynamically instable patients
• age under 18 and over 85 years,
• heart failure not caused by coronary artery disease
• Severe co-morbidity

Patients admitted to the hospital with a left ventricular ejection fraction (LVEF) under 35%, due to coronary artery disease with an indication for electrophysiological investigation.