“ Searching the heart ” involves no medical exam of the literal heart, which in 70 or 80 years might beat some three billion times.
فَقَدْ قَالَ :‏ « اَلْقَلْبُ أَشَدُّ غَدْرًا مِنْ كُلِّ شَيْءٍ ،‏ وَهُوَ يَسْتَمِيتُ إِلَى غَايَتِهِ .‏