Gemignani Vincenzo, Bianchini Elisabetta, Faita Francesco, Lionetti Vincenzo, Campan Manuela, Recchia Fabio Anastasio, Picano Eugenio, Bombardini Tonino
National Research Council, Institute of Clinical Physiology, Pisa, Italy.
Pacing Clin Electrophysiol. 2010 Jul;33(7):795-803. doi: 10.1111/j.1540-8159.2009.02684.x. Epub 2010 Jan 27.
Invasively measured left ventricular (LV) dP/dt is the accepted standard for measuring acute and chronic directional changes in LV contractility. Recently, we developed a noninvasive force sensor based on an accelerometer positioned on the chest, which measures the vibrations generated by isovolumic myocardial contraction. The aim of this paper was to compare noninvasive (accelerometer) versus invasive (LV dP/dt) indices of myocardial contractility in a chronic minipig model of pacing-induced heart failure (HF). Comparative assessment was performed both at rest and following dobutamine infusion.
In adult male minipigs (n = 6), LV contractility was simultaneously assessed both invasively (LV dP/dt, Millar catheter) and noninvasively (accelerometer) at rest and following dobutamine (up to 7.5 mcg/kg/min), both before and after development of HF by pacing the LV at 180 beats/min for 3 weeks.
Invasive and noninvasive assessments were obtained in 24 conditions (12 at rest and 12 after dobutamine infusion). Sensor-based cardiac force changes were significantly related to positive peak LV dP/dt(max) changes following dobutamine infusion both in normal (r = 0.88, P < 0.001) and failing heart (r = 0.89, P < 0.001). The force-frequency relation showed a tight correlation between invasive and noninvasive assessment (r = 0.68, P = 0.02).
The force-frequency relation can be assessed noninvasively by a transthoracic sensor based on an accelerometer. The method can efficiently detect the development of resting dysfunction and the contractile reserve at different HF steps, with potential for wearable HF monitoring.
有创测量的左心室（LV）dp/dt是测量LV收缩力急性和慢性方向变化的公认标准。最近，我们开发了一种基于置于胸部的加速度计的无创力传感器，该传感器可测量等容心肌收缩产生的振动。本文的目的是在起搏诱导的心力衰竭（HF）慢性小型猪模型中比较无创（加速度计）与有创（LV dp/dt）心肌收缩力指标。在休息时和多巴酚丁胺输注后进行比较评估。
在成年雄性小型猪（n = 6）中，在通过以180次/分钟的频率起搏LV 3周诱导HF之前和之后，在休息时以及多巴酚丁胺（高达7.5 mcg/kg/min）输注后，同时通过有创（LV dp/dt，Millar导管）和无创（加速度计）评估LV收缩力。
在24种情况下获得了有创和无创评估结果（12次在休息时，12次在多巴酚丁胺输注后）。在正常心脏（r = 0.88，P < 0.001）和衰竭心脏（r = 0.89，P < 0.001）中，基于传感器的心脏力变化与多巴酚丁胺输注后LV dp/dt（max）的正向峰值变化显著相关。力-频率关系显示有创和无创评估之间紧密相关（r = 0.68，P = 0.02）。
基于加速度计的经胸传感器可无创评估力-频率关系。该方法可有效检测不同HF阶段静息功能障碍的发展和收缩储备，具有用于可穿戴HF监测的潜力。
