Ischaemic Heart Disease Flashcards
IHD
IHD = an imbalance between myocardial oxygen supply and demand, associated with inadequate arterial supply via the coronary arteries.
- IHD is commonly caused by atherosclerosis.
- Atheroma and inappropriate vasoconstriction reduce blood vessel lumen size and coronary blood flow. When oxygen demand > oxygen supply, myocardial hypoxia, accumulation of waste metabolites and ischaemia ensues.
- IHD syndromes include angina (stable and unstable) and myocardial infarction.
Angina
Chest pain caused by insufficient supply of oxygenated blood supply to the myocardium by the coronary arteries.
Stable Angina
Predictable transient chest pain during exertion or emotional stress. Ischaemia with symptoms resolve once oxygen balance is restored
Stable Angina Signs and Symptoms
Constricting chest pain(can radiate to the neck, L shoulder / arm and jaw), worsened by exertion, relieved by rest. SOB, sweating, nausea.
Unstable Angina
Unpredictable / occurs at rest. Plaque disruption initiates platelet aggregation, thrombus formation and vasoconstriction. May be a precursor to acute MI.
Angina: Risk factors
- Cigarette smoking ― linked to endothelial dysfunction, CAS,vessel wall injury, oxidative stress, elevates fibrinogen, platelet activation and inflammation. Smoking cessation in angina can prevent recurrent angina events.
- Vitamin D deficiency ― significant correlation between vitamin D deficiency and chronic angina. Improves endothelial function by signalling for the transcription of eNOS; modulates the RAAS to lower BP.
- Family historyof premature IHD is a strong risk factor for angina.
Myocardial Infarction (MI)
MI = an acute blockage of a coronary artery usually due to a thrombus, resulting in the death of myocardial tissue.
* Prolonged ischaemia leads to myocardial necrosis. Ischaemic myocardial cells release adenosine and lactate onto nerve endings causing pain.
* Infarcted areas produce scar tissue. The remaining tissue hypertrophies and can result in cardiac dysfunction and heart failure.
MI: Causes and risk factors
- Sex: Males ~ 3 times more likely to experience MI. High androgen levels contribute to development of atherosclerosis.
- Psychosocial factors: Stress (e.g., financial). Loss of locus of control, sudden life events (e.g., job loss, marital separation) increase MI risk.
- Others: Drug-induced (cocaine), significant myocardial O2 demand (e.g., severe hypertension) or reduced O2 supply (e.g., severe anaemia), vasculitis syndromes (e.g., temporal arteritis).
MI Signs and Symptoms
Severe prolonged crushing retrosternal chest pain. Pain radiates to the left shoulder, jaw / neck or arms. Sweating, cool / clammy skin. Feeling of ‘impending doom’. Dyspnoea and syncope. Nausea, vomiting, weakness.
Natural Approach to IHD
Apply the Natural Approach to CVD, with a focus on supporting myocardial blood flow. Key considerations:
* Optimise vitamin D status –supports endothelial health and promotes vasodilation (↑ NO).
* Warming herbs / spices to support blood flow, e.g., ginger, cayenne.
* Increasing movement—care is needed to avoid triggering angina attacks —focus on gentle exercise i.e., Tai Chi, Qi Gong, walking. Gradually increase as capacity improves.
* Address stress. Breathing exercises. Nervine herbs (e.g., passionflower1–2 tsps dried herb 2–3 x per day (infusion)
IHD: Nutrients
L-carnitine
Magnesium
Hawthorn
CoQ10
L-arginine
Ginkgo biloba
IHD: L-carnitine
Dose: 1000mg x2/day
Improves FA utilisation and myocardial ATP production, which may also prevent the production of toxic FA metabolites. These would normally impact cardiac cell membranes = impaired myocardial contractility.
IHD: Magnesium
Dose: 200 - 400mg x3/day
Magnesium deficiency has been shown to produce coronary artery spasms. Magnesium controls the movement of calcium into smooth muscle cells, leading to smooth muscle contraction. Deficiency also ↑ ROS.
IHD: Hawthorn
Dose: 1000 - 1500mg
Its flavonoids have been shown to be responsible for dilating the coronary arteries.
IHD: CoQ10
Dose 100 to 300mg daily
- Increases eNOS and NO*, improves ED function and vascular elasticity.
- Exerts anti-inflammatory effects –lowers TNF-α and IL-6. NF-κB can be inhibited by CoQ10’s anti-oxidant activity.
