Cardiothoracic Surgery Flashcards
What is the definition of sinus rhythm?
- P-wave precedes each QRS and every P-wave is followed by a QRS
- P-wave axis is normal (positive in leads I and aVR)
- Rate is normal between 60-100bpm
Verapamil/diltiazem combined with beta-blockers can cause symptomatic sinus bradycardia or AV block.
What is the most common type of primary lung tumours?
Bronchogenic carcinoma
(Epithelial lung tumours)
- Small cell lung cancer
- Non-small-cell lung cancer
>> Squamous cell carcinoma
>> Adenocarcinoma
>> Large cell undifferentiated cancer
What is the most common type of primary lung tumour in nonsmokers?
Adenocarcinoma of the lung (Non-small-cell bronchogenic/epithelial lung tumour/carcinoma)
What are the risk factors for lung cancer?
- Smoking
>> Cigarette (10-30X)
>> Cigar
>> Pipe
>> Second-hand - Asbestos
>> Without smoking (RR5)
>> With smoking (RR92) - Metals
>> Chromoium
>> Arsenic
>> Nickel - Radon gas
- Ionizing radiation
- Genetics
What are the signs and symptoms of lung cancer?
Can be due to primary lesion**, **metastasis** or **paraneoplastic syndrome
- *PRIMARY LESION**
- Cough: chronic cough with changes in character
- Dyspnea
- Chest pain/Other sources of pain
- Hemoptysis
- Finger clubbing
- Constitutional symptoms: anorexia, weight loss, fever, anemia
METASTASIS
- Pleural effusion, wheezing: lung, hilum, mediastinum, pleura
- Pericardial tamponade, pericarditis: pericardium
- Dysphagia: esophageal compression
- Paralyzed diaphragm: phrenic nerve
- Hoarseness: recurrent laryngeal nerve
- Superior vena cava syndrome
>> Neck and facial swelling
>> Dyspnea
>> Cough
>> Physical findings:
** Increased collaterals over the anterior chest wall
** Edema of face, arms and chest
** Pemberton’s sign: raising both arms above head
^^ Facial flushing
^^ Cyanosis
^^ Distension of neck veins
- Horner’s syndrome, brachial plexus palsy: Pancoast tumour
- Distant metastasis to brain, bone, liver and adrenals
- *Paraneoplastic Syndrome**
- Most often associated with small cell lung cancer
- SCLC: Cushing’s syndrome (ACTH), SIADH, Lambert-Eaton syndrome
- NSCLC: clubbing, hypertrophic pulmonary osteoarthropathy (HPOA), Trousseau’s syndrome (migratory thromboplebitis)
- Bronchogenic cancer: acanthosis nigricans, dermatomyositis, nonbacterial endocarditis
- Squamous cell cancer: hypercalcemia (osteolysis/PTHrP), hypophosphatemia
- Others: nephrotic syndrome, DIC
What is EBUS (endobronchial ultrasound)?
- Allows visualization of peri-bronchial structures and distal peripheral lung lesions
- Provides detailed assessment of airway wall layers
- Allows for guided biopsies of lymph nodes and tumours
For diagnosis and staging
2/3rds of primary lung cancer are found in the UPPER LUNG.
2/3rds of metastases occur in the LOWER LUNG – hematogenous spread secondary to increased blood flow to the base of the lung.
Why is small cell lung carcinoma (SMLC) named as such?
Cytopathology will reveal cells smaller than normal ones, with barely any room left for the cytoplasm —- problems with controlling the size of the cell
Also known as “oat cell lung carcinoma”
- Highly malignant
- Paraneoplastic syndromes
>> Ectopic ACTH
>> Ectopic ADH —– SIADH
>> Lambert-Eaton Myasthenic Syndrome (LEMS) - Divided into two clinicopathological stages
>> Limited stage: combination chemotherapy and concurrent curative RT +/- prophylactic brain treatment
>> Extensive stage: comibination chemotherapy +/- palliative RT
What investigations should be ordered in a patient with suspected primary lung malignancy?
- *Bloodwork**
- CBC
- RFT
- LFT
- Calcium
- *Imaging**
- CXR
- CT chest and abdomen +/- pelvis
- PET scan
- Bone scan
- Neuroimaging
- *Cytology**
- Spum
- *Biopsy**
- Bronchoscopy/EBUS
- Percutaneous mediastinoscopy
- Mediastinotomy
- Thoracotomy
What are the median survival rates for small cell lung cancer?
- Limited stage
>> 1-2 years with treatment
>> 12 weeks without treatment - Extensive stage
>> 6 months with treatment
>> 6 weeks without treatment
How is small cell lung carcinoma staged?
- Limited stage (LS-SCLC)
- Confined to a single radiation port
- i.e. One hemithorax and regional lymph nodes - Extensive stage (ES-SCLC)
- Extension beyond a single radiation port
How is non-small cell lung cancer (NSCLC) staged?
TNM staging
What are the causes of aortic stenosis?
- Congenital: bicuspid/unicuspid valve
- Acquired – calcification
- Acquired – rheumatic disease
How is aortic stenosis classified?
By aortic valve area
Normal: 3-4cm2
- Mild: 1.5-3cm2
- Moderate: 1.0-1.5cm2
- Severe: <1.0cm2
- Critical: <0.5cm2
