Hi
Welcome to the MedHelp forum!
Apart from cardiac causes there are many other causes for blackouts and passing out. I am just enumerating the possible causes. You can discuss this with your doctor and get yourself examined. Dizziness could be due to postural hypotension (blood pressure falling with change of position), internal ear problems and cervical spondylitis or compression of cervical spinal nerves. All these cause dizziness when you get up from lying down position or when you change position that results in a change in the level of your head. Cervical spondylitis and ear problems also cause dizziness on changing the position of the neck.
Other causes are anemia, claustrophobia, GERD, hypoglycemia or low sugar and some endocrine problems. Endocrine problems, such as an underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease), low blood sugar levels, and in some cases, diabetes, may lead to hypotension and hence lightheadedness and an off balance feeling.
Certain types of epilepsies and seizures too can cause similar symptoms. If your father has an accompanying headache then you must also look at benign intracranial hypertension. Heart problems have been ruled out in his case. If all other tests are normal, maybe an ECHO should be done to rule out mitral valve prolapse. It can also be chronic fatigue syndrome if all other causes are ruled out.
Hope this helps. Do discuss this with your father’s doctor and get him examined accordingly. Please let me know if there is any thing else and do keep me posted. Take care!
Is he still on medication for his irregular heartbeat?
My husband has atrial fibrillation which caused similar symptoms.
Has he had a echocardiogram and a thalium stress test?
He might need his medication changed.
Good luck!