Download The normal ECG Cardiac cycle and cardiac sounds/ Pressure

The normal ECG
Cardiac cycle and cardiac sounds/ Pressure changes in atria and ventricles
Syllabus
ECG
General description
Leads and Vectors (Including Einthoven’s triangle)
P wave
P-R interval
QRS complex
ST segment
T wave
Q-T interval
Non-Pacemaker action potentials
- Phase 0
- Phase 1
- Phase 2
- Phase 3
- Phase 4
Refractory period
- Absolute
- Relative
Pacemaker action potentials
- Phase 0
- Phase 3
- Phase 4
Regulation of conduction
Regulation of pacemaker activity
Cardiac cycle and cardiac sounds/ Pressure changes in atria and ventricles
Atrial systole
Isovolumetric ventricular contraction
Ventricular Ejection
Isovolumetric ventricular relaxation
Ventricular filling
Wiggers diagram
- ECG
- Heart sounds
- Left ventricular pressure
- Aortic pressure
- Carotid pressure
- Radial pressure
- Right ventricular pressure
- Pulmonary artery pressure
- Left atrial pressure
- Jugular venous pressure
- Left ventricular volume
Questions
1) A 65 year old female is admitted to ICU after an elective AAA repair. Two hours after
admission her blood pressure is 95/55 and HR 115/min. She is a known hypertensive.
a) Draw normal CVP trace (10)
b) Draw the waveforms produced as one inserts a pulmonary artery catheter (20)
c) Discuss the role of the CVP and pulmonary artery catheter as monitors of intravascular
volume (20)
2 a) Compare and contrast the actional potentials of a left ventricular cardiomyocyte and the
sinoatrial node (30)
b) Discuss the regulation of pacemaker activity (15)
c) Discuss the cardiac refractory period (5)
References
1) Review of Medical Physiology. William F. Ganong. 22nd Edition. Chapters 28 and 29
2) Miller’s Anaesthesia. Ronald D. Miller. 7th Edition. Chapter 40 - Cardiovascular Monitoring
3) CVphysiology.com
Pathophysiology of myocardial ischaemia, shock, hypertension and
cardiac failure
1) Myocardial Ischaemia
a) Pathogenesis of atherosclerosis
b) Pathophysiology of chronic stable angina
c) Pathophysiology of unstable angina/NSTEMI
d) Pathophysiology of STEMI
e) Pathophysiology of perioperative myocardial infarction
References:
a) Choose a standard medical textbook for basic pathophysiology.
I advise: Harrison’s Principles of Internal Medicine. Kasper, Braunwald, Fauci, et al. 16th
Edition or later.
If you are using 16th Ed then:
224: The pathogenesis of atherosclerosis
226: Ischemic heart disease
227: Unstable angina and non-ST-elevation myocardial infarction
228: ST-segment elevation myocardial infarction
Focus on the pathophysiology sections of the above unless very keen to expand horizons.
b) Peroperative cardiac events in patients undergoing noncardiac surgery: a review of the
magnitude of the problem, the pathophysiology of the events and methods to estimate
and communicate risk. Devereaux, PJ; et al. CMAJ 2005; 173(6):627-34
2) Shock
a) Cardiovascular pathophysiology-especially sepsis
Reference:
Sepsis and the Heart. Merx, MW; Weber, C. Circulation 2007; 116: 793-802.
3) Hypertension
a) Essential
- Pathophysiology
- Target organ effects
b) Secondary
- Renal
- Endocrine
- Neurogenic
- Drugs
- Miscellaneous
References:
a) Choose standard medical textbook as basic reference.
Again I advise Harrison’s.
230: Hypertensive vascular disease-focus on pathophysiology
b) Stoelting’s Anaesthesia and Co-existing Disease. Hines, RL; Marschall, KE. 5th Edition.
Chapter 5: Systemic and Pulmonary Hypertension-focus on first section on
Pathophysiology.
c) Is a rethink of our approach to hypertension necessary? Coetzee, A; Levin, A. SAJAA;
November 2005: 117-123
4) Cardiac failure
a) Systolic
b) Diastolic
Reference
Heart Failure. Jessup, M; Brozena, S. NEJM 2003; 348:2007-18
Myocardial blood flow and metabolism
Syllabus
Anatomy
- Epicardial coronary arteries & territories
- Microanatomy
Coronary blood flow
- ml/min
- ml/100g/min
- % of cardiac output
Coronary perfusion pressure
Variation of coronary blood flow with cardiac cycle
Control of coronary blood flow
Measurement of coronary blood flow
Myocardial oxygen consumption and oxygen extraction ratio
Myocardial metabolism
Myocardial supply-demand balance
Stunning
Hibernation
Ischaemic preconditioning
Questions
1) A 59 year old male patient presents for a hemicolectomy. He is diabetic, hypertensive and a smoker
with a 30 pack-year history. During surgery there is significant blood loss and he becomes tachycardic
and hypotensive. ST segment depression is noted.
a) Compare and contrast myocardial blood flow to the right and left ventricles. (10)
b) Discuss the determinants of myocardial oxygen delivery. (20)
c) Discuss strategies to improve myocardial oxygen balance that may be of relevance to the above
patient. (20)
References
1) Review of Medical Physiology. William F. Ganong. 22nd Edition. Chapter 32-Circulation Through Special
Regions and Chapter 29-Origin of the Heartbeat & Electrical Activity of the Heart.
2) Clinical Anesthesiology. G. Edward Morgan, Maged S. Mikhail, Michael J. Murray. 4th Edition. Chapter
19-Cardiovascular Physiology & Anesthesia.
3) CVphysiology.com