557 - Members; certain disabilities.
§ 557. Members; certain disabilities. Notwithstanding any provision of this chapter or of any general, special or local law to the contrary, any condition of impairment of health caused by diseases of the heart, resulting in disability or death to a member shall be presumptive evidence that it was incurred in the performance and discharge of duty and the natural and proximate result of an accident, unless the contrary be proved by competent evidence.