Initial treatment of claudication = walking

 Patients who follow an exercise regimen can increase their walking time by 150%.  A supervised program may produce better results.  Risk factors include diabetes mellitus, hypertension, smoking, and hyperlipidemia.  Unconventional treatments such as chelation have not been shown to be effective.  Vasodilating agents are of no benefit.  There is no evidence that anticoagulants such as aspirin have a role in the treatment of claudication

In a patient who presents with symptoms of acute myocardial infarction, which one of the following would be an indication for thrombolytic therapy? 

new left bundle branch block suggests occlusion of the left anterior descending artery,

At present there is no approved treatment for Raynaud’s disease. However, patients with this disorder reportedly experience subjective symptomatic improvement with calcium channel antagonists. Nifedipine is the calcium channel blocker of choice in patients with Raynaud’s disease. Beta-blockers can produce arterial insufficiency of the Raynaud type, so propranolol and atenolol would be contraindicated. Drugs such as ergotamine preparations and methysergide can produce cold sensitivity, and should therefore be avoided in patients with Raynaud’s disease.

a moderately elevated plasma homocysteine concentration is an independent risk factor for atherothrombotic vascular disease

LDL level for patients with diabetes mellitus or coronary artery disease is <100 mg/dL. Many may not realize that this goal extends to people with CAD-equivalent diseases, including peripheral artery disease, symptomatic carotid artery disease, and abdominal aortic aneurysm.

Beta-blockers with intrinsic sympathomimetic activity (ISA) are less beneficial in reducing mortality post myocardial infarction, and for this reason are not recommended for ischemic heart disease. They have a potential advantage in only one clinical situation. Since they tend to lower heart rates less, they may be beneficial in patients with symptomatic bradycardia while taking other beta-blockers. All beta-blockers should be used cautiously in patients with diabetes or asthma. Only sotalol, which delays ventricular depolarization, has been shown to be effective for maintenance of sinus rhythm in patients with chronic atrial fibrillation

Although the significance of elevated triglycerides and a low HDL in low-risk patients is somewhat uncertain, in a high-risk patient such as a diabetic, improvement in these results will lower the risk of subsequent cardiac events. In diabetics, metformin and thiazolidinediones (e.g., rosiglitazone) are more likely to improve lipid levels than are sulfonylureas. Nicotinic acid is problematic in diabetics, as it tends to cause deterioration in glucose control. Fibrates are good choices for this patient because they will lower the triglyceride level and raise the HDL level. Exercise and weight loss are likely to be helpful as well. Cholestyramine will raise triglyceride levels.

Neurosurgical procedures, particularly those with penetration of the brain or meninges, and orthopedic surgeries, especially those of the hip, have been linked with the highest incidence of

venous thromboembolic events. The risk is due to immobilization, venous injury and stasis, and impairment of natural anticoagulants. For total knee replacement, hip fracture surgery, and total hip replacement, the prevalence of DVT is 40%-80%, and the prevalence of pulmonary embolism is 2%-30%. Other orthopedic procedures, such as elective spine procedures, have a much lower rate, approximately 5%

Patients with peripheral vascular disease who stop smoking have a twofold increase in their 5-year survival rate. Diet modification and lipid-lowering drugs can slow progression, but not as dramatically. Aspirin and pentoxifylline are minimally effective.

Hypertrophic cardiomyopathy is an autosomal dominant condition and close relatives of affected individuals should be screened. The hypertrophy usually stays the same or worsens with age. This patient should not participate in strenuous sports, even those considered noncontact. Beta-blockers have not been shown to alter the progress of the disease

Based on recent clinical trials, the most common recommendation for surgical repair is when the aneurysm approaches 5.5 cm in diameter.

Syncope with exercise is a manifestation of organic heart disease in which cardiac output is fixed and does not rise (or even fall) with exertion. Syncope, commonly on exertion, is reported in up to 42% of patients with severe aortic stenosis. Vasovagal syncope is associated with unpleasant stimuli or physiologic conditions, including sights, sounds, smells, sudden pain, sustained upright posture, heat, hunger, and acute blood loss. Transient ischemic attacks are not related to exertion. Orthostatic hypotension is associated with changing from a sitting or lying position to an upright position. Atrial myxoma is associated with syncope related to changes in position, such as bending, changing from sitting to lying, or turning over in bed

Since this patient’s mean aortic-valve gradient exceeds 50 mm Hg and the aortic-valve area is not larger than 1 cm2, it is likely that his symptoms are due to aortic stenosis. As patients with symptomatic aortic stenosis have a dismal prognosis without treatment, prompt correction of his mechanical obstruction with aortic valve replacement is indicated. Medical management is not effective, and balloon valvotomy only temporarily relieves the symptoms and does not prolong survival. Patients who present with dyspnea have only a 50% chance of being alive in 2 years unless the valve is promptly replaced. Exercise testing is unwarranted and dangerous

Most decision trees for the evaluation of hyponatremia begin with an assessment of volume status; edema reflects volume overload and increased total body sodium caused by congestive heart failure, cirrhosis, or renal failure. If edema is absent, plasma osmolality should be determined. SIADH, Addison’s disease (hypoadrenalism), diuretic use, and renal artery stenosis all lower serum osmolality. Urine electrolytes help distinguish the other conditions: psychogenic polydipsia causes low urine sodium, while SIADH and hypoadrenalism cause inappropriately elevated urine sodium. Diuretic use, a very common cause of hyponatremia in the geriatric population, causes hypovolemic hyponatremia and can be associated with either high or low urine sodium, but there is often

concomitant hypokalemia. Ref: Goh KP: Management of hyponatremia. Am Fam Physician 2004;69(10):2387-2394.

The risk of pulmonary embolism is five times higher in pregnant women than in nonpregnant women of similar age, and venous thromboembolism is a leading cause of illness and death during pregnancy. Warfarin, which readily crosses the placenta, should be avoided throughout pregnancy. It is definitely teratogenic during the first trimester, and extensive fetal abnormalities have been associated with exposure to warfarin in any trimester. Because heparin does not cross the placenta, it is considered the safest anticoagulant to use during pregnancy. Initially, patients with venous thromboembolism during pregnancy should be managed with heparin given according to the recommendations for nonpregnant patients. These women should receive intravenous heparin for 5–10 days followed by subcutaneous heparin for the duration of the pregnancy. Warfarin can be given after delivery, since it is not present in breast milk. The indications for placement of an inferior vena cava filter are not changed by pregnancy, and include any contraindication to anticoagulant therapy, the occurrence of heparin-induced thrombocytopenia, and recurrence of pulmonary embolism in a patient receiving adequate anticoagulant therapy. There are no data to support the use of aspirin for treatment or prophylaxis of pulmonary embolism either during or after pregnancy.

According to several randomized, controlled trials, mortality rates are improved in patients with heart failure who receive beta-blockers in addition to diuretics, ACE inhibitors, and occasionally, digoxin. Contraindications to beta-blocker use include hemodynamic instability, heart block, bradycardia, and severe asthma. Beta-blockers may be tried in patients with mild asthma or COPD as long as they are monitored for potential exacerbations. Beta-blocker use has been shown to be effective in patients with NYHA Class II or III heart failure. There is no absolute threshold ejection fraction. Beta-blockers have also been shown to decrease mortality in patients with a previous history of myocardial infarction, regardless of their NYHA classification. 

. Patients who are not currently experiencing unstable coronary syndrome, severe valvular disease, uncompensated congestive heart failure, or a significant arrhythmia are not considered at high risk, and should be evaluated for most surgery primarily on the basis of their functional status. If these patients are capable of moderate activity (greater than 4 METs) without cardiac symptoms, they can be cleared with no stress testing or coronary angiography for an elective minor or intermediate-risk operation such as the one this patient is to undergo. A resting 12-lead EKG is recommended for males over 45, females over 55, and patients with diabetes, symptoms of chest pain, or a previous history of cardiac disease. Ref: ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery--Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). Circulation 2002;105(10):1257-1267.

Patients with Wolff-Parkinson-White syndrome who have episodic symptomatic supraventricular tachycardia or atrial fibrillation benefit most from: Radiofrequency catheter ablation of bypass tracts is possible in over 90% of patients and is safer and more cost effective than surgery, with a similar success rate. Intravenous and oral digoxin can shorten the refractory period of the accessory pathway,

and increase the ventricular rate, causing ventricular fibrillation. Beta-blockers will not control the ventricular response during atrial fibrillation when conduction proceeds over the bypass tract. 

Elevated blood pressure along with physical findings of cardiovascular disease establishes the diagnosis of hypertension in this patient, so it is not necessary to take follow-up blood pressure readings prior to starting treatment. Since he has no symptoms or physical findings suggestive of secondary hypertension it is also not necessary to perform a laboratory workup prior to treatment. Because he has Stage 3 hypertension with evidence of end-organ disease, treatment with antihypertensives is indicated at this point. At least three large clinical trials, including the European Working Party on High Blood Pressure in the Elderly (EWPHE) trial, have shown that diuretics are the most effective single agents for hypertension in the elderly. A low-sodium diet can be added, as can a beta-blocker if the hypertension fails to respond to diuretics alone.

any person with elevated LDL cholesterol or any other form of hyperlipidemia should undergo clinical or laboratory assessment to rule out secondary dyslipidemia before initiation of lipid-lowering therapy. Causes of secondary dyslipidemia include diabetes mellitus, hypothyroidism, obstructive liver disease, chronic renal failure, and some medications

In pregnant women with severe hypertension, the primary objective of treatment is to prevent cerebral complications such as encephalopathy and hemorrhage. Intravenous hydralazine, intravenous labetalol, or oral nifedipine may be used. 

Clinical predictors of increased perioperative cardiovascular risk for elderly patients include major risk factors such as unstable coronary syndrome (acute or recent myocardial infarction, unstable angina), decompensated congestive heart failure, significant arrhythmia (high-grade AV block, symptomatic ventricular arrhythmia, supraventricular arrhythmias with uncontrolled ventricular rate), and severe valvular disease. Intermediate predictors are mild angina, previous myocardial infarction, compensated congestive heart failure, diabetes mellitus, and renal insufficiency. Minor predictors are advanced age, an abnormal EKG, left ventricular hypertrophy, left bundle-branch block, ST and T-wave abnormalities, rhythm other than sinus, low functional capacity, history of stroke, and uncontrolled hypertension. Ref: Schroeder BM: Updated guidelines for perioperative cardiovascular evaluation for noncardiac surgery. Am Fam Physician 2002;66(6):1096-1107.

When treating arrhythmias related to cocaine toxicity, hypertonic sodium bicarbonate and benzodiazepines may be given when the distinction between sodium channel blockade–induced QRS-complex widening and ischemia-induced ventricular tachycardia is unclear. Lidocaine may subsequently be utilized if necessary. Verapamil has been shown to reverse cocaine-induced coronary vasospasm. Beta-adrenergic blocking drugs have been shown to exacerbate coronary vasospasm by resulting in unopposed alpha-adrenergic activity. Beta-blockers are therefore contraindicated in the treatment of cocaine-induced cardiac problems

Atenolol and propranolol are associated with intrauterine growth retardation when used for prolonged periods during pregnancy. They are class D agents during pregnancy. Other beta-blockers

may not share this risk. Methyldopa, hydralazine, and calcium channel blockers have not been associated with intrauterine growth retardation. They are generally acceptable agents to use for established, significant hypertension during pregnancy

If possible, NSAIDs should be avoided in patients with heart failure. They cause sodium and water retention, as well as an increase in systemic vascular resistance which may lead to cardiac decompensation. Patients with heart failure who take NSAIDs have a tenfold increased risk of hospitalization for exacerbation of their CHF. NSAIDs alone in patients with normal ventricular function have not been associated with initial episodes of heart failure. NSAIDs, including high-dose aspirin (325 mg/day), may decrease or negate entirely the beneficial unloading effects of ACE inhibition. They have been shown to have a negative impact on the long-term morbidity and mortality benefits that ACE inhibitors provide. Sulindac and low-dose aspirin (81 mg/day) are less likely to cause these negative effects

Five recent randomized, controlled trials have indicated that in most patients with atrial fibrillation, an initial approach of rate control is best. Patients who were stratified to the rhythm control arm of the trials did NOT have a morbidity or mortality benefit and were more likely to suffer from adverse drug effects and increased hospitalizations. The most efficacious drugs for rate control are calcium channel blockers and beta-blockers. Digoxin is less effective for rate control and should be reserved as an add-on option for those not controlled with a beta-blocker or calcium channel blocker, or for patients with significant left ventricular systolic dysfunction. In patients 65 years of age or older or with one or more risk factors for stroke, the best choice for anticoagulation to prevent thromboembolic disease is warfarin. Of note, in patients who are successfully rhythm controlled and maintained in sinus rhythm, the thromboembolic rate is equivalent to those managed with a rate control strategy. Thus, the data suggest that patients who choose a rhythm control strategy should be maintained on anticoagulation regardless of whether they are consistently in sinus rhythm.

Cilostazol is a drug with phosphodiesterase inhibitor activity introduced for the symptomatic treatment of arterial occlusive disease and intermittent claudication. Cilostazol should be avoided in patients with congestive heart failure. There are no limitations on its use in patients with previous stroke or a history of diabetes. It has been found to have beneficial effects on HDL cholesterol levels and in the treatment of third degree heart block

Beta-blockers and ACE inhibitors have been found to decrease mortality late after myocardial infarction. Aspirin has been shown to decrease nonfatal myocardial infarction, nonfatal stroke, and vascular events. Nitrates, digoxin, thiazide diuretics, and calcium channel antagonists have not been found to reduce mortality after myocardial infarction

Most women with mild, uncomplicated essential hypertension are at minimal risk for cardiac complications within the short time frame of pregnancy. There is no evidence available that treatment of mild essential hypertension during pregnancy provides any benefit to the mother. Given the potential for short- and long-term risk to the fetus from antihypertensive treatment, it is advisable to discontinue antihypertensive treatment, monitor the mother for signs of preeclampsia, and monitor fetal growth and development. Medication is not necessary as long as the systolic blood

pressure remains below 160 mm Hg, the diastolic blood pressure remains below 105–110 mm Hg, and there are no signs of preeclampsia or fetal growth restriction. Should the mother develop severe hypertension, treatment can be initiated with long-acting nifedipine, labetalol, a thiazide diuretic, or methyldopa. Atenolol has been associated with reduced fetal growth, and ACE inhibitors are contraindicated in the second and third trimesters.

With subclinical thyroid dysfunction, TSH is either below or above the normal range, free T3 or T4 levels are normal, and the patient has no symptoms of thyroid disease.  Subclinical hypothyroidism (TSH >10 µU/mL) is likely to progress to overt hypothyroidism, and is associated with increased LDL cholesterol.  Subclinical hyperthyroidism (TSH <0.1 µU/mL) is associated with the development of atrial fibrillation, decreased bone density, and cardiac dysfunction.

This patient has classic signs of hypothyroidism.  Of the drugs listed, only lithium is associated with the development of hypothyroidism.  In patients taking lithium, it is recommended that in addition to regular serum lithium levels, thyroid function tests including total free T4, and TSH be obtained yearly. 

Lithium therapy can elevate calcium levels by elevating parathyroid hormone secretion from the parathyroid gland.  This duplicates the laboratory findings seen with mild primary hyperparathyroidism.  If possible, lithium should be discontinued for 3 months before reevaluation (SOR C).  This is most important for avoiding unnecessary parathyroid surgery

Delayed gastric emptying may be caused or exacerbated by medications for diabetes, including amylin analogues (e.g., pramlintide) and glucagon-like peptide 1 (e.g., exenatide).  Delayed gastric emptying has a direct effect on glucose metabolism, in addition to being a means of reducing the severity of postprandial hyperglycemia.  In a clinical trial of exenatide, nausea occurred in 57% of patients and vomiting occurred  in 19%, which led to the cessation of treatment in about one-third of patients.  The other medications listed do not cause delayed gastric emptying.

renal failure precludes the use of metformin

Although uncommon, pituitary disease can cause secondary hypothyroidism.  The characteristic laboratory findings are a low serum free T4 and a low TSH.  A free T4 level is needed to evaluate the proper dosage of replacement therapy in secondary hypothyroidism.  The TSH level is not useful for determining the adequacy of thyroid replacement in secondary hypothyroidism since the pituitary is malfunctioning. In the initial evaluation of secondary hypothyroidism, a TRH stimulation test would be useful if TSH failed to rise in response to stimulation.  It is not necessary in this case, since the diagnosis has already been made.

A patient with a recurrent kidney stone and an elevated serum calcium level most likely has hyperparathyroidism, and a parathyroid hormone (PTH) level would be appropriate.  Elevated PTH is caused by a single parathyroid adenoma in approximately 80% of cases.  The resultant hypercalcemia is often discovered in asymptomatic persons having laboratory work for other reasons.  An elevated PTH by immunoassay confirms the diagnosis.  In the past, tests based on renal responses to elevated PTH were used to make the diagnosis.  These included blood phosphate,

chloride, and magnesium, as well as urinary or nephrogenous cyclic adenosine monophosphate.  These tests are not specific for this problem, however, and are therefore not cost-effective.  Serum calcitonin levels have no practical clinical use.