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Question we did in class today. Just wondering if someone could explain to me why ASD would cause decreased in residual volume and total lung capacity? thanks
A 52-year-old male presented to the respiratory outpatient clinic with a history of progressive breathlessness on exertion.
He was a keen rambler, and had first noticed his symptoms some twelve months previously when he was struggling to keep up with his wife.
He had no associated cough, sputum production, wheeze or chest pain. His past medical history included a transient ischaemic attack (TIA) three months previously, seasonal allergic rhinitis and hypercholesterolaemia. He was a lifelong non-smoker and had been started on aspirin and simvastatin since his TIA. He admitted that his diet was poor and contained a significant amount of saturated fats.
On clinical examination he was found to be obese (BMI 30) and plethoric. His blood pressure was 100/80 mmHg, Temperature 36.8°C, pulse 96 beats per minute and oxygen saturations of 90% on room air. On auscultation there was an ejection systolic murmur loudest in the left second intercostal space.
His ECG showed right axis deviation with right bundle branch block.
His full pulmonary function tests are shown below:
Actual % Predicted
FVC 4.30 L 87%
FEV1 3.62 L 84%
FEV1/FVC 84% 99%
TLC 6.90 L 86%
RV/TLC 30.0 % 110%
DLCO (ml/m/mm Hg) 56 mL /m/mm Hg 163%
What is the most likely underlying diagnosis?
(Please select 1 option)
1.Atrial septal defect This is the correct answer
2.Chronic pulmonary emboli
3.Cor pulmonale Incorrect answer selected
4.Obstructive sleep apnoea
5.Pulmonary restriction secondary to obesity
The history of a recent TIA, along with the clinical and ECG findings, are consistent with an atrial septal defect.
The grossly elevated DLco is secondary to the left-right shunt and increased pulmonary blood flow. In contrast, chronic pulmonary emboli will cause a low DLco. Although the patient has a mild ventilatory defect secondary to obesity, this does not explain the clinical findings.
Other causes of a raised DLco include asthma, obesity, exercise, polycythaemia and any cause of alveolar haemorrhage (Goodpasture's syndrome, Wegener's granulomatosis, etc).
A 52-year-old male presented to the respiratory outpatient clinic with a history of progressive breathlessness on exertion.
He was a keen rambler, and had first noticed his symptoms some twelve months previously when he was struggling to keep up with his wife.
He had no associated cough, sputum production, wheeze or chest pain. His past medical history included a transient ischaemic attack (TIA) three months previously, seasonal allergic rhinitis and hypercholesterolaemia. He was a lifelong non-smoker and had been started on aspirin and simvastatin since his TIA. He admitted that his diet was poor and contained a significant amount of saturated fats.
On clinical examination he was found to be obese (BMI 30) and plethoric. His blood pressure was 100/80 mmHg, Temperature 36.8°C, pulse 96 beats per minute and oxygen saturations of 90% on room air. On auscultation there was an ejection systolic murmur loudest in the left second intercostal space.
His ECG showed right axis deviation with right bundle branch block.
His full pulmonary function tests are shown below:
Actual % Predicted
FVC 4.30 L 87%
FEV1 3.62 L 84%
FEV1/FVC 84% 99%
TLC 6.90 L 86%
RV/TLC 30.0 % 110%
DLCO (ml/m/mm Hg) 56 mL /m/mm Hg 163%
What is the most likely underlying diagnosis?
(Please select 1 option)
1.Atrial septal defect This is the correct answer
2.Chronic pulmonary emboli
3.Cor pulmonale Incorrect answer selected
4.Obstructive sleep apnoea
5.Pulmonary restriction secondary to obesity
The history of a recent TIA, along with the clinical and ECG findings, are consistent with an atrial septal defect.
The grossly elevated DLco is secondary to the left-right shunt and increased pulmonary blood flow. In contrast, chronic pulmonary emboli will cause a low DLco. Although the patient has a mild ventilatory defect secondary to obesity, this does not explain the clinical findings.
Other causes of a raised DLco include asthma, obesity, exercise, polycythaemia and any cause of alveolar haemorrhage (Goodpasture's syndrome, Wegener's granulomatosis, etc).
