What are the reasons for chest tightness and stuffiness in pregnant women?

Patient's question:

Main symptoms in the past week: Chest congestion, shortness of breath
Doctor's diagnosis and test results: I am pregnant and have been experiencing chest congestion and heavy breathing recently. The electrocardiogram showed: heart rate 112 beats per minute, insufficient blood supply to the heart muscle, sinus tachycardia. The cardiologist said they dare not prescribe medication and advised me to rest at home and regulate my condition. I hope the doctor can give me some guidance.
What kind of help do you want: What causes chest tightness and congestion in pregnant women?

Doctor's answer:

You are a pregnant woman, how many months are you pregnant now? Have all your prenatal check-ups been normal? As the pregnancy progresses, the pressure on your abdomen will become increasingly intense. It is normal to feel stuffy, but if you start needing to breathe heavily, it may not be something you can manage on your own. You should go to the hospital for treatment and coordinate medication and oxygen therapy. Since medication during pregnancy is very strict, it is recommended that you consult a traditional Chinese medicine doctor with extensive clinical experience to take your pulse and diagnose the condition, and then confirm a reasonable treatment plan.