In a system and method for monitoring cardiac synchrony in a human heart, a first sensor is positioned at a first cardiac wall location that is subject to movements related to longitudinal valve plane movements along the longitudinal axis of the heart, and measures the cardiac wall movements at the first cardiac wall location and a second sensor is positioned at a second cardiac wall location that is subject to movements related to longitudinal valve plane movements along the longitudinal axis of the heart, and measures the cardiac wall movements at the second cardiac wall location. A lead arrangement conducts respective output signals from the first and second sensors to processing circuitry that processes the first and second sensor output signals to produce a synchronization signal therefrom indicative of synchrony in the respective valve plane movements at the first and second cardiac wall locations.