She was born with a weak heart.

她生来就有一个衰弱的心脏。

《牛津词典》

She suffered from a weak heart.

她心脏不好。

《牛津词典》

She tired easily and had a weak heart.

她容易疲劳，心脏也比较弱。

《柯林斯英汉双解大词典》

They may have a weak or damaged heart, high blood pressure or other problems of the blood system.

VOA: special.2010.07.27

He had a weak heart but a sharp mind.

FORBES: Magazine Article

Dr. Frank Stegall, a cardiologist at Redmond Regional Medical Center in Rome, told Gonzalez he had a chronically weak heart, or dilated cardiomyopathy.

CNN: Guatemalan in Atlanta awaits word on possible heart transplant

One might expect that at the ripe old age of 100 the company would be creaking along with brittle bones, weak knees, a bad heart, and finding it hard to get up in the morning.

FORBES: Happy 100th Birthday IBM!