CFB PBL 1 Flashcards
Describe the funtion of heart chambers and valves
- Atria recieve incoming blood
-muscular ventricles pump blood out of heart
-valves prevent backflow of blood
-tricuspid located between RA and RV
-bicsuspid (mitral) LA/ LV
-semilunar - aortic + pulmonary
Describe the phsysiology of heart sounds
CREATED AS A RESULT OF CLOSING OG HEART VALVES + TURBULANCE OF BLOOD FLOW
S1 (LUBB) - low frequency heart sound, caused by AV valve closing - during isovolumetric contraction, beginning of ventricular systole
S2 DUBB - less loud than S1, caused by closure of semi-lunar valves during isovolumetric relaxation, marks beginning of ventricular diastole
S3: caused by vibration of hypertrophic ventricular walls (heart walls become stiff) during early diastole
happens during passive filling (not good, worse because vibrations occuring with no other force)
This is normal in chilren, but in adults may indicate SYSTOLIC VENTRICULAR FAILURE
S4: Caused by viibration of hypertrophic ventricular walls
during late diastole
during active filling
heard in patients with VENTRICULAR HYPERTROPHY, MYOCARDIAL ISCHEMIA, ELDERLY PATIENTS (because associated with a stiffined ventricle)
Descrive AV valve incompetence and stenosis
AV valve INCOMPETENCE: Valves do not CLOSE properly, backwatds flow of blood
AV valce STENOSIS: do not OPEN properly (narrowing of valves prevent sufficient blood from leaving heart)
Describe heart mummers
Whoosing / Swishing noise caused by rapid / choppy blood flow through heart
Types:
- PHYSIOLOGICAL: caused by exercise and agae (harmless)
- Developmental (congenital): caused when valves in heart do not close after birth (congenital defects)
-Pathological: caused by calcium deficiency, hole between ventricular walls, overactvive throid
Causes of pan-systolic and late diastolic murmors
PAN SYSTOLIC:
AV valve prolapse. Throughout ventricular systole
LATE DIASTOLIC:
Due to stenosis (AV valve not opening properly), causes turbulance
Throughout ventricular diastole
Describe how valvular heart disease can lead to left ventricular enlargement
Mitral stenosis leads to reduced ventricular filling
Leads to reduced EDV
Leads to reduced preload, muscle stretch
Leads to reduced ejection fraction + contraction force
Leads to reduced stroke volume
Leads to reduce cardiac output and BP
Leads to LEFT VENTRICULAR ENLAREGEMENT (to overcome low stroke vol)
Describe how mitral valve dissease causes abnormal intra-cardiac pressure and pulmonary pressure
Mitral valve disease
Give an overview of the pathological basis of rheumatic heart disease
RHEUMATIC FEVER: throat infection caused by streptococus bacteria. Causes autoimmune response. Leads to inflammation + scarring of heart layers + valve stenosis/incompetence
How is the autoimmune response caused?
MOLECULAR MIMICARY
-antigens of streptrocoal bacteria mimic heart cells causing T cells to attack our own cells
MAC (major histocompatability complex): present homologous pathogenic antigens, similar to heart cells to immune system, resulting in autoimmune response EG.
Attacking our own heart cells
Causes of heart disease
Repeated infection by group A streptococal bacteria
Respiratory exam + Cardiovascular exam:
-enlarged heart because heart is in between 2nd rib and 6th intercostal space instead of 5th.
Mid systolic and late diastolic murmurs
X-Ray - heart size too big
Echocardiogram (ultrasound) - large left ventricle + incompetent mital valve
Treatment for heart disease
Surgery to replace valve
Beta blockers to lower BP + improve ejection fraction
Diuretics - prevent fluid build up, may lead to further conditions such as liver failure
Signs + Symptoms of Rheumatic Heart Disease
Under 25
-Fever
-Joint pain
-Fatigue
-Feet swelling
-Rapid Heart Rate
-Fatigue
Repeated infection by group A steptococus bacteria
Autoimmune response
Attacks joints, heart
Attacks heart valves - inflammation + scarring of valves
Valve regurgitation / Valve leaking (stenosis / incompetence occurs)
