engleski

VF Detection Utilizing the Lead Bending Sensor

Purpose of study was to use the cardiac contraction sensor for VF detection. Our previous experiments showed that cardiac contractions bend the cardiac lead and modulate its high frequency (HF) parameters whereby reflection coefficient waveform correlates to LV dp/dt waveform. We did HF measurements in 6 patients during ICD implantations. Directional coupler was connected in parallel with ICD sensing/pacing lead conductor to ZVB20 network analyzer (Rohde&Schwarz, USA). Calibration procedure was done at 50 MHz. VF episode was induced and defibrillation was done utilizing implanted ICD. ECG, ventricular IEGM, HF signal and chest X-ray fluoroscopy were synchronously recorded during VF. We were able to record HF signal modulation, caused by lead bending, in all patients. HF wave occurred during systole always after QRS complex. It instantly disappeared upon VF induction and recovered with sinus rhythm recovery after DC shock. Every standard cardiac lead may be cardiac contraction sensor without any device mounted on it. Additional HF hardware and algorithms would not significantly decrease battery longevity of ICD. Future study should investigate hemodynamic stability of different ventricular arrhythmias utilizing same system

cardiac leads; pacemakers; sensor; ventricular fibrillation

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