You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A 60-year-old male hypeensive had a stroke 2 weeks prior to this sudden attack of dyspnea. The present ECG shows changes of S1 Q3 T3 and the V/Q pulmonary scan shows major areas of reduced perfusion. What is the probable diagnosis? and explain in detail?
Dyspnoea is the most common symptom of pulmonary embolism,and tachypnoea is the most common sign.ECG in pulmonary embolism shows sinus tachycardia ,and S1Q3T3 sign-an S wave in lead I,a Q wave in lead III,and an inveed T wave in lead III.V/Q scan can be done if there is no previous cardiopulmonary disease,& it shows major areas of reduced perfusion due to increased pulmonary vascular resistance & impaired gas exchange. Reference:Harrison's medicine-18th edition,page no:2170-2172;Davidson's medicine-22nd edition,page no:722.