Dentist Notes

Cardiology

PathologyUpdated 3 min read
On this page 9 sections

One Liners

  1. Essential = Hyaline Arteriolosclerosis
  2. Malignant = Fibrinoid Necrosis
  3. Libmann Sack endocarditis valve = Mitral and aortic

Heart Anatomy

Coronary ArteryMain Regions SuppliedKey Branches
Left Anterior Descending (LAD)Heart apex, anterior 2/3 of interventricular septum, anterior LV wallDiagonal branches, Septal perforators
Left Circumflex (LCX)Lateral and posterior LV walls, left atriumObtuse Marginal branches
Right Coronary Artery (RCA)Right atrium, right ventricle, SA node (~60%), AV node (~90%)SA Nodal branch, Right Marginal artery
Posterior Descending (PDA)Inferior LV wall, posterior 1/3 of septum, posterior RV wallArises from RCA (85%) or LCX (8%)

Valvular Diseases

ValveOpens between
MitralLA → LV
TricuspidRA → RV
AorticLV → Aorta
PulmonaryRV → Pulmonary artery
LesionTimingCharacterLocationRadiation
Aortic stenosisSystolicCrescendo-decrescendoRUSBCarotids
Aortic regurgitationDiastolicEarly diastolic blowingLSB—
Mitral stenosisDiastolicRumbling + opening snapApex—
Mitral regurgitationSystolicHolosystolicApexAxilla
Tricuspid regurgitationSystolicHolosystolicLLSB—
Tricuspid stenosisDiastolicRumblingLLSB—
Pulmonary stenosisSystolicEjectionLUSB—
Pulmonary regurgitationDiastolicBlowingLUSB—
DiseaseOverloadChamber affected
Aortic stenosisPressureLV
Aortic regurgitationVolumeLV
Mitral stenosisPressureLA → pulmonary circulation → RV
Mitral regurgitationVolumeLA + LV
Pulmonary stenosisPressureRV
Pulmonary regurgitationVolumeRV
Tricuspid stenosisPressureRA
Tricuspid regurgitationVolumeRA/RV

Heart Sound Auscultation Landmarks

Mitral Valve (Apex): 5th left intercostal space in the midclavicular line.

Aortic Valve: 2nd right intercostal space at the sternal border.

Pulmonic Valve: 2nd left intercostal space at the sternal border.

Tricuspid Valve: 4th or 5th left intercostal space at the lower left sternal border.

Murmur hint

Aortic valve

Should be OPEN during systole

→ Aortic stenosis = systolic

Should be CLOSED during diastole

→ Aortic regurgitation = diastolic

Mitral valve

Should be OPEN during diastole

→ Mitral stenosis = diastolic

Should be CLOSED during systole

→ Mitral regurgitation = systolic

MI

BiomarkerInitial RisePeak LevelNormalization / Duration RaisedClinical Utility & High-Yield Notes
Myoglobin1–3 hours6–9 hours24 hoursEarliest to rise; good for ruling out early MI, but low specificity (found in skeletal muscle).
Troponin I (cTnI)3–4 hours18–24 hours7–10 daysGold Standard; highly cardiac-specific.
Troponin T (cTnT)3–4 hours18–24 hours10–14 daysStays elevated slightly longer than cTnI.
CK-MB4–6 hours12–24 hours2–3 days (48–72 hrs)Best marker for detecting re-infarction due to its quick return to baseline.
AST / SGOT12–24 hours24–48 hours3–4 daysHistorical marker; rarely used today due to low cardiac specificity.
LDH (LDH-1)24–48 hours48–72 hours7–14 daysUsed for late-presenting MIs prior to modern troponin assays.

Four major causes of oedema

MechanismExamplesWhy oedema occurs
Increased capillary hydrostatic pressureHeart failure, venous obstruction, fluid overloadMore fluid is pushed out of capillaries
Decreased plasma oncotic pressureNephrotic syndrome, cirrhosis, severe malnutritionReduced plasma protein osmotic pull
Increased capillary permeabilityInflammation, burns, allergic reactionsFluid and proteins escape more readily
Lymphatic obstructionLymph node dissection, lymphatic damage, filariasisInterstitial fluid and protein clearance is impaired

FCPS pearl: Oedema can result from increased filtration, reduced plasma oncotic pressure, increased permeability, or inadequate lymphatic drainage.