Drugs that are Contraindicated in Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy ( HCM ) is a condition in which the heart muscles enlarge and thicken to become blind drunk and less compliant to variety in diastolic pressing . The alteration mostly move the left heart ventricle , which is responsible for supplying blood to the peripheral tissues . The disease is largely genetic in etiology with associate environmental crusade such as hypertension , diabetes mellitusandhyperthyroidism .
The risk of develop the disease increases with age . Hypertrophic cardiomyopathy present with features of decompensated heart failure such as body swelling and cough due to fluid overload and difficulty in breathing among other features . Sudden cardiac catch is also a common exigency presentment of the condition require emergency brake care .
The disease poses various challenges in diagnosis and direction such as :
Hemodynamic Changes of Hypertrophic Cardiomyopathy
In a normal fondness , the chambers should unwind adequately in diastole to countenance for influx of enough rakehell . This spring the basis of adequate contraction in systole as limn by the frank sterling law that provides “ the more the heart muscles stretch out the more the power achieved in contraction ” . Similarly , a placid passage without obstruction and valve insufficiency is see in a normal heart .
change receive in hypertrophic cardiomyopathy include :
Inadequate Contraction and loosening : The thickened heart brawn contract bridge and unbend inadequately . Hence , there is insufficient filling of the chamber with blood during diastole and consequently insufficient pumping of blood during systole resulting in reduced cardiac output and features of heart loser in extreme case . This is worsened by harden of the valves that become floppy and regurgitant . This type of cardiomyopathy is known as hypertrophic non - obstructive cardiomyopathy ( HNOCM )
Blood Passage Contraction : Thickening direct to contraction of the lineage passages and thus causes hypertrophic impeding cardiomyopathy ( HOCM ) .
Low Electric Activity : The muscles badly conduct the electrical activity of the heart and thus may lead to arrhythmias .
Pharmacological Treatment of Hypertrophic Cardiomyopathy
Given the hemodynamic change above , the intervention should direct at lowering the pressure slope across the ventricular outflow nerve pathway and reducing the hearts ionotropic body process , more so in hindering states . Thus , the drugs of choice here include drug with β - blocker body process which function by prolong the diastolic woof time and hence reduce the heart rate and improve the obstacle .
In a case where β - blocker are not effective verapamil - type calcium channel blockers are advocate as they have been shown to better diastolic map . Cordarone is the only factor that has been rise to be beneficial in reducing the natural event of arrhythmias .
Relative contraindication survive in the usage of diuretics such as hydrochlorothiazide and angiotensinogen exchange enzyme inhibitor ( ACEIs ) such as enalapril and Zestril . These drugs are safe as long as close monitoring is done and once an obstructive lesion is documented the drug must be cease .
Absolute contraindication is advocated with the use of nitrates , nifedipine type - Ca channel blockers and plus ionotropic drug such as digitalis . These drugs have been shown to increase the cardiac output in a compromised ticker , thus aggravate the outflow tract obstruction and hence heart loser manifestations .
Conclusion
In summary , hypertrophic cardiomyopathy is a common disease that is largely genetic , but with associated environmental etiologies whose diagnosis and management can be challenging . Of furthermost importance , is to document the presence or absence of an clogging wound and the ejection fraction at diagnosis as they form the base of pharmacologic therapy . Nitrates , ACEIs , nifedipine type - atomic number 20 channel blocking agent and plus inotropes are contraindicated in the treatment of this disease as the increase cardiac turnout and worsen the features of ventricular outflow obstruction .
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