Blunt Cardiac Injury
OVERVIEW
Blunt Cardiac Injury: spectrum from asymptomatic with minor enzyme rises to fulminant cardiac failure
INJURIES
Cardiac injury
- 90% are lethal within minutes
- direct impact or pressure transmitted fixed and mobile parts (atriocaval disruptions)
Pericardial injury
- direct thoracic injury or indirect from acute increase in intra-abdominal pressure
- can cause significant herniation of through tear and cardiac dysfunction
Valvular injury
- aortic > mitral > tricuspid > pulmonary
- sudden increase in intrathoracic pressure -> laceration or avulsion of aortic cusps
- violent compression of heart in systole -> tearing of mitral valve leaflets and papillary muscle rupture
Septal injury
- rupture causes a loud holosystolic murmur or conduction abnormalities
Coronary artery injury
- rare
- cause dissection and thrombosis
- LAD most susceptible
- angioplasty / stent is the treatment of choice
Myocardial Contusion
- look for chest pain, pericardial rub, S3, cardiac failure
- ECG: ST or T wave changes anteriorly, heart blocks, incomplete RBBB, inferior Q waves
- ECHO: contractility, RWMA
- TNT elevation
HISTORY
- mechanism
- restrained
- airbags
- other injuries: sternal fractures, major chest wall injury (flail segment, haemopnemothorax, aortic injury)
- comorbidities: IHD, cardiomyopathy, pacemaker, AICD
- medications: beta-blockers, anti-arrhythmics
EXAMINATION
- observations: P, BP, SpO2, GCS
- CVS: peripheral perfusion, JVP, heart sounds (muffled, S3, rub, cyanosis), signs of heart failure, shock
- RESP: tenderness, sternal fractures, clavicle integrity, tracheal position, haemo/pneumothorax
INVESTIGATIONS
- CXR
- ECHO: RWMA, contractility, valvulopathy, tamponade
- CT chest: aortogram
- TNT
- ECG: ST changes, TW changes, blocks, RBBB
MANAGEMENT
- -> surgery (if indicated)
- -> angiography (if indicated)
- -> supportive
- -> monitoring for arrhythmias
- -> replace electrolytes
- -> inotropes
- -> IABP
References and Links
- Parr MJ. Blunt cardiac injury. Minerva Anestesiol. 2004 Apr;70(4):201-5. Review. PubMed PMID: 15173696. [Free Full Text]
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC