“What are the potential cardiac causes for chest tightness?”

Doesn’t sound cardiac to me
But you shd see PCP to rule it out , anxiety , GERD , and costo chondritis / asthma are common

The most common cardiac cause of chest tightness or pressure is angina which is caused by restriction of the blood flow to the heart muscle. The most common cause of angina is coronary artery disease which involves narrowing of the arteries by plaque build up. Features of angina are typically chest pain/heaviness/tightness/pressure which comes on with exertion and improves with rest. While there are other non-cardiac causes of chest tightness, it's a good idea to discuss the symptoms with a healthcare professional to determine the cause.