Heart contraindications

Valve Problems. The primary solution to valve problems has been implantable replacement valves. The introduction of these devices necessitates open-heart surgery. There are two types of valves available tissue (porcine and bovine) and mechanical. The disadvantage of tissue valves is that these have a limited life of about seven years before they calcify, stiffen, and have to be replaced. The mechanical valves can last a lifetime, but require anticoagulant therapy. In some patients, anticoagulants may not be feasible or may be contraindicated. Of the valves which require replacement, 99% are mitral and aortic valves. The valves on the left side of the heart are under much greater pressure because the left ventricle is pumping blood out to the entire body, instead of only to the lungs. Occasionally, two valves are replaced in the same procedure. 

Under certain circumstances, and very rarely, the inhibition of gluconeogenesis by metformin may suppress lactic acid metabolism and precipitate a potentially fatal lactic acidosis. Impairment of renal function, liver disease, alcoholism, conditions that give rise to increased lactate production (e.g. congestive heart failure, infections) are therefore contraindications for the application of metformin. 

These drags are contraindicated in patients with an allergy to the (3 blockers, in patients with sinus bradycardia, second- or third-degree heart block, heart failure, and those with asthma, emphysema, or hypotension. The drug are used cautiously in patients with diabetes, thyrotoxicosis, and peptic ulcer. 

Both carvedilol and labetalol are contraindicated in patients with hypersensitivity to the drag, bronchial asthma, decompensated heart failure, and severe bradycardia The drugs are used cautiously in patients with drag-controlled congestive heart failure, chronic bronchitis, impaired hepatic or cardiac function, in those with diabetes, and during pregnancy (Category C) and lactation. 

Other contraindications for die anticholinergics include tachyarrhythmias, myocardial infarction, and congestive heart failure (unless bradycardia is present). 

The MAOI antidepressant drag s are contraindicated in patients widi known hypersensitivity to die drug s, liver and kidney disease, cerebrovascular disease, hypertension, or congestive heart failure and in die elderly. These drag s are given cautiously to patients witii impaired liver function, history of seizures, parkinsonian symptoms, diabetes, or hyperthyroidism. 

Metformin is contraindicated in patients with heart failure, renal disease, hypersensitivity to metformin, and acute or chronic metabolic acidosis, including ketoacidosis. The drug is also contraindicated in patients older than 80 years and during pregnancy (Pregnancy Category B) and lactation. 

These drugp are contraindicated in patients with known hypersensitivity to the drug or to any constituents of the drug, after a recent myocardial infarction (heart attack), or in patients with thyrotoxicosis. When hypothyroidism is a cause or contributing factor to a myocardial infarction or heart disease, the physician may prescribe small doses of thyroid hormone... 

Ergonovine is contraindicated in those with known hypersensitivity to the drug, hypertension, and before the delivery of the placenta Ergonovine is used cautiously in patients with heart disease obliterative vascular disease, renal or hepatic disease and during lactation. 

Potassium is contraindicated in patients who are at risk for experiencing hyperkalemia, such as those with renal failure, oliguria, or azotemia (file presence of nitrogen-containing compounds in the blood), anuria, severe hemolytic reactions, untreated Addison s disease (see Chap. 50), acute dehydration, heat cramps, and any form of hyperkalemia Potassium is used cautiously in patients with renal impairment or adrenal insufficiency, heart disease, metabolic acidosis, or prolonged or severe diarrhea. Concurrent use of potassium with... 

Sodium is contraindicated in patients with hypernatremia, fluid retention, and when the administration of sodium or chloride could be detrimental. Sodium is used cautiously in surgical patients and those with circulatory insufficiency, hypoproteinemia, urinaiy tract obstruction, congestive heart failure, edema, and renal impairment. Sodium is a Pregnancy Category C drug and is used cautiously during pregnancy. 

There are a few absolute contraindications for deep peeling, mainly physical or mental instability. During pregnancy and lactation any cosmetic intervention is considered undesirable. All patients are required to perform electrocardiogram and complete blood count prior to the procedure. Any heart disease requires special precautions and it is always recommended to work in cooperation with the patient s cardiologist. 

Contraindications are the same as for immunotherapy for inhalant allergy, but are relative in nature because of the life-saving potential of venom immunotherapy. Elderly patients, especially with preexisting cardiovascular disease, are at a high risk to develop severe or even fatal anaphylaxis [26]. Therefore, venom immunotherapy is often recommended in patients over 50-60 years of age. Since (3-blocker treatment is associated with a significantly increased survival rate in patients with coronary heart... 

Serious adverse effects of epinephrine potentially occur when it is given in an excessive dose, or too rapidly, for example, as an intravenous bolus or a rapid intravenous infusion. These include ventricular dysrhythmias, angina, myocardial infarction, pulmonary edema, sudden sharp increase in blood pressure, and cerebral hemorrhage. The risk of epinephrine adverse effects is also potentially increased in patients with hypertension or ischemic heart disease, and in those using (3-blockers (due to unopposed epinephrine action on vascular Ui-adrenergic receptors), monoamine oxidase inhibitors, tricyclic antidepressants, or cocaine. Even in these patients, there is no absolute contraindication for the use of epinephrine in the treatment of anaphylaxis [1,5,6]. 

To control risk factors and prevent major adverse cardiac events, statin therapy should be considered in all patients with ischemic heart disease, particularly in those with elevated low-density lipoprotein cholesterol. In the absence of contraindications, angiotensin-converting enzyme inhibitors should be considered in ischemic heart disease patients who also have diabetes melli-tus, left ventricular dysfunction, history of myocardial infarction, or any combination of these. Angiotensin receptor blockers... 

Blockers are contraindicated in patients with severe bradycardia (heart rate less than 50 beats per minute) or AV conduction defects in the absence of a pacemaker. (3-Blockers should be used with particular caution in combination with other agents that depress AV conduction (e.g., digoxin, verapamil, and diltiazem) because of increased risk for bradycardia and heart block. Relative contraindications include asthma, bronchospastic disease, severe depression, and peripheral vascular disease. (3,-Selective blockers are preferred in patients with asthma or chronic obstructive pulmonary... 

In randomized, controlled, clinical trials, calcium channel blockers were as effective as p-blockers at preventing ischemic symptoms. Calcium channel blockers are recommended as initial treatment in IHD when /3-blockers are contraindicated or not tolerated. In addition, CCBs may be used in combination with /3-blockers when initial treatment is unsuccessful. However, the combination of a (1-blocker with either verapamil or diltiazem should be used with extreme caution since all of these drugs decrease AV nodal conduction, increasing the risk for severe bradycardia or AV block when used together. If combination therapy is warranted, a long-acting dihydropyridine CCB is preferred. (3-Blockers will prevent reflex increases in sympathetic tone and heart rate with the use of calcium channel blockers with potent vasodilatory effects. 

STE and NSTE ACS, class I recommendation in all patients without contraindications for oral P-blockers, class I (NSTE ACS) and I la (STE ACS) for IV P-blockers, class lib recommendation for patients with moderate left ventricular failure with signs of heart failure provided they can be closely monitored. 

STE ACS, class I recommendation within the first 24 hours after hospital presentation for patients with anterior wall infarction, clinical signs of heart failure and those with EF less than 40% in the absence of contraindications, class I la recommendation for all other patients in the absence of contraindications. 

Intravenous or oral doses of a P-blocker should be administered early in the care of a patient with STE ACS, and then oral agents should be continued indefinitely. Early administration of a P-blocker to patients lacking a contraindication within the first 24 hours of hospitalization is a quality care indicator.2,3 In ACS the benefit of P-blockers mainly results from the competitive blockade of P,-adrenergic receptors located on the myocardium. Pi-Blockade produces a reduction in heart rate, myocardial contractility, and blood pressure, decreasing myocardial oxygen demand. As a result of these effects, P-blockers reduce the risk for recurrent ischemia, increase in infarct size and risk of reinfarction, and occurrence of ventricular arrhythmias in the hours and days following MI.39... 

Adverse effects and contraindications of calcium channel blockers are described in Table 5-2. Verapamil, diltiazem, and first-generation dihydropyridines should also be avoided in patients with acute decompensated heart failure or left... 

As described in the previous section, calcium channel blockers should not be administered to most patients with ACS. Their role is a second-line treatment for patients with certain contraindications to P-blockers and those with continued ischemia despite P-blocker and nitrate therapy. Administration of either amlodipine, diltiazem, or verapamil is preferred.2 Agent selection is based on heart rate and left ventricular dysfunction (diltiazem and verapamil are contraindicated in patients with bradycardia, heart block, or systolic heart failure). Dosing and contraindications are described in Table 5-2. 

---