How many letters does the top answer for “of or pertaining to or affecting both the heart and the lungs and their functions” have?

The most common answer is cardiopulmonary (15 letters).

Crossword clue: of or pertaining to or affecting both the heart and the lungs and their functions

cardiopulmonary, cardiorespiratory.

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

cardiopulmonary 15 letters wn-def

of or pertaining to or affecting both the heart and the lungs and their functions

cardiorespiratory 17 letters wn-def

of or pertaining to or affecting both the heart and the lungs and their functions