--- module: 009-02 language: en chapter: 9 title: "Ischaemia, Heart Failure, Valve Disease, and Arrhythmia" module_title: "Coronary flow, congestion phenotypes, and structural decision-making" source_sha256: db81fc2b7f111e17a3dd9071ee46211e623f708de4f3392e9719a8ed0041fe73 --- # Coronary flow, congestion phenotypes, structural decisions ## Coronary flow and perfusion ### Epicardial arteries and resistance vessels ### Collateral channels ### Perfusion pressure and diastolic time ### An open artery with microvascular limitation ### Collaterals beyond a chronic severe stenosis ### Anatomy, flow and injury are not identical ## Plaque and thrombus ### Lipid retention and inflammation ### Smooth-muscle response and matrix turnover ### Vulnerability beyond percentage narrowing #### Cap integrity and inflammatory activity #### Core composition and mechanical stress ### Disruption exposes thrombogenic material ### Platelets adhere, thrombin forms fibrin ## Ischaemia and injury ### Metabolism and relaxation change first ### Then contraction and electrical properties ### Membrane integrity fails if severe and prolonged ### Wall-motion change precedes necrosis markers ### Electrical instability from altered ion gradients ### Imbalance without acute plaque thrombosis #### Tachyarrhythmia, hypertension, hypoxaemia, anaemia #### The wrong label adds bleeding risk ## Troponin and ischaemic evidence ### A rise or fall shows dynamic injury ### Infarction needs ischaemic causation #### Symptoms and electrocardiographic evolution #### New regional imaging change or coronary thrombus ### Sampling interval and assay precision ### Chronic elevation with structural or kidney disease ### Compare with previous values and trajectory ### One non-diagnostic tracing does not dismiss risk ## Congestion, perfusion, diuresis ### Wet or dry by filling pressure ### Warm or cold by peripheral perfusion ### Cold congestion means limited reserve ### Warm limbs do not exclude high pressures ### Left-sided: interstitial oedema, poor compliance ### Right-sided: raised systemic venous pressure ### Renal venous hypertension cuts filtration ### Natriuretic peptides need context #### Obesity suppresses concentration #### Age, kidneys, atrial fibrillation raise it ### Diuretic delivery, tubular secretion, sodium load ### Apparent resistance: adherence, absorption, dose ## Disease-modifying therapy ### Renin-angiotensin-aldosterone blockade ### Evidence-based beta blockade ### Mineralocorticoid receptor antagonism ### Sodium-glucose cotransporter two inhibition ### Titrate against pressure, potassium, kidneys ### An early filtration change is not always injury ### Preserved ejection fraction is heterogeneous #### A normal resting study can miss exertional pressure ## Valve lesions as loads ### The gradient rises with flow ### Low gradient despite severe narrowing ### Integrate area, gradients, function, symptoms ### Chronic regurgitation allows chamber adaptation ### Acute regurgitation has no time to adapt ### Loudness follows flow and pressure difference ### Intervene before irreversible damage ## Atrial fibrillation and embolism ### Electrical and structural disease together ### Stretch, fibrosis, inflammation, autonomic triggers ### Rapid activation drives further remodelling ### Rate control limits the ventricular response ### Rhythm control by cardioversion, drugs, ablation ### Neither strategy removes stroke-risk assessment ### Stasis, endothelial change, prothrombotic state ### Bleeding review finds modifiable hazards ### Mechanical recovery lags electrical restoration ## Integrating mechanisms ### One deterioration, several mechanisms ### Ischaemia weakens contraction and provokes regurgitation ### Rapid atrial fibrillation unmasks valve disease ### Name the dominant mechanism, not every abnormality ### Trajectory after treatment tests the causal model ## Discharge and follow-up after intervention ### Rest-time improvement is not long-term stability ### Residual congestion, standing pressure, walking tolerance ### Name the symptoms that warrant early contact ### Fix the up-titration plan, test timing and who reviews ### Residual microvascular disease after revascularisation ### Recovery after valve treatment, recurrence after ablation