A heart monitoring system (100) comprises an array of force-sensitive resistors (10) spanning a sensor surface (50). Each resistor (10) is configured to change a respective resistance value (R) in accordance with an amount of static pressure (P) exerted on the sensor surface (50) at a respective location of the force-sensitive resistor (10) by a subject (200). An array of piezoelectric transducers (20) is interspersed among the array of force-sensitive resistors (10). Each transducer (20) is configured to generate 10 a respective time-dependent electrical signal (S) in accordance with respective vibrations (F) exerted on the sensor surface (50) at a respective location of the transducer (20) by the subject (200). A controller (30) is configured to determine a heart rate (H1) of the subject (200) based on a combination of the measured resistance values (R) of the force-sensitive 15 resistors (10) and the time-dependent electrical signals (S) of the piezoelectric transducers (20).