Talk to Psychiatry on Heart SVT Or Panic Disorder

my brother has GAD genetically, after few years he was diagnosed with Heart PVC so doctors perscribed concor 2.5 then he was allright. he married but divorced in one month after that one days he was walking at walking track with thoughts of divorce and suddeny panic attack occured, panic attack finished in 10 minutes, next day he went to hospital with me for ECG but when ecg prob fixed on his chest he became panic with tachcardia so he said to put off the prob from his chest. when we put off prob his beat became normal any way again v tried and his beat super fast but ecg done. now phycatrist says he has panic attack and cardiologist says he has heart svt as per ecg result. right now he has fear of stucking in rush, traffic jam or going to malls or feel uncomfortable to be away from his own car. he is taking zoloft 50 mg and he is 50% fine but he still remain in fear. some time he takes xanax 0.25 before going to any gathering. he says when he suffer tachycardia that is terrible for