18: Systemic Disorders and their Clinical Implications

Systemic Disorders and their Clinical Implications

Cardiovascular Disorders

Hematological Disorders

➧. Red Blood Cell Disorders

➧. Polycythemia

➧. Anemia

➧. Thalassemia

➧. White Blood Cell Disorders

➧. Qualitative Disorders

➧. Non-neoplastic Disorders

➧. Neoplastic Disorders

➧. Bleeding Disorders

➧. Vascular Disorders (Vessel Wall)

➧. Platelet Disorders

➧. Thrombocytopathic Disorders

➧. Thrombocytopenic Disorders

➧. Disorders of Coagulation

➧. Inherited Coagulation Disorders

➧. Acquired Coagulation Disorders

Respiratory Disorders

Renal Disorders

Gastrointestinal Disorders

Neuromuscular Disorders

Endocrinal Disorders

➧. General Overview of Disorders of Endocrine System

➧. Growth Hormone

➧. Disorders of Posterior Pituitary (Neurohypophysis)

➧. Thyroid Gland

➧. Disorders Associated with Thyroid Gland

➧. Parathyroid Glands

➧. Hypothalamus–Pituitary–Adrenal Axis

➧. Pregnancy

➧. Saliva and Monitoring of Hormone Levels

Mental Health and its Relevance to Dentistry

Cardiovascular Disorders

Cardiovascular disease is quite common, though more frequent and severe in later life, can also affect young individuals. It is one of the leading causes of death in the world. A thorough knowledge of cardiovascular diseases is necessary because of its implications in dentistry and also the initial measures taken by the dentists in case of certain emergency conditions can be lifesaving.

Symptoms Suggestive of Cardiovascular Disease

Breathlessness or Dyspnea

It is a major symptom of many cardiac disorders, particularly left heart failure. Dyspnea may vary in severity from an uncomfortable awareness of breathing to a frightening sensation of fighting for breath.

There are three forms of dyspnea:

Edema of legs

Bilateral swelling of the legs due to edema is a common feature of chronic heart failure.

The history should also determine the patient’s functional capacity.

The functional capacity can be graded as:

Patients are at an increased cardiac risk when unable to meet a 4 MET demand during normal daily activity.

Physical examination

The general appearance of the patient can provide valuable information related to his/her physical and emotional state. Pallor, cyanosis, peripheral edema, dyspnea, tremors, Cheyne–Stokes respiration, obesity and anxiety are clues that suggest the presence of cardiovascular disease.

Common Cardiovascular Disorders and Their Dental Considerations

Hypertension

Hypertension is a disorder characterized by an abnormal elevation of arterial pressure, which if sustained and untreated, is associated with a significant increase in morbidity and mortality. The systolic or diastolic pressure or both are elevated in hypertension.

It may be asymptomatic for long periods but ultimately leads to damage with resultant symptoms in several organs including kidney, heart, brain and eyes.

It is generally accepted that a sustained systolic blood pressure of 140 mmHg or more and a sustained diastolic blood pressure of 90 mmHg or more is abnormal.

Signs and symptoms

A patient with hypertension is usually asymptomatic for quite a few years. The early symptoms include occipital headache, vision changes, ringing ears, dizziness, weakness and nose bleeding. Odontalgia due to hyperemia or congestion of dental pulp has also been reported.

Untreated hypertension reduces the life span by 10–20 years. Even mild hypertension that has not been treated for 7–10 years increases the risk of complications. Sustained hypertension results in arterial damage (atherosclerosis) and the onset of these vascular changes in the kidney, cardiovascular system, cerebrovascular system and eyes can cause complications such as renal failure, coronary insufficiency, myocardial infarction, congestive cardiac failure, cerebrovascular accident (stroke) and blindness in patients. Malignant hypertension develops in 1% of hypertensives. The chief complication is severe ischemic damage to kidney and renal failure. In the absence of treatment, it can be fatal within 1 year of diagnosis.

Blood pressure is measured by the use of a sphygmomanometer, an instrument that indirectly records the diastolic and systolic pressure.

Food, exercise, alcohol and smoking should be avoided for 30 minutes before measurement of BP and also the patient should be at rest for at least 5 minutes.

Faulty BP readings involve using improper size cuffs or applying the cuffs too loosely or too tightly.

Classification of blood pressure

Classification Systolic BP (mmHg) Diastolic BP (mmHg)
Normal <120 <80
Pre-hypertension 120–139 80–90
Stage 1 hypertension 140–159 90–99
Stage 2 hypertension >160 >100

Specific management

Antihypertensive therapy

image Direct-acting vasodilators: Nitroglycerin and minoxidil directly relax vascular smooth muscle. Methyldopa and clonidine act in the CNS to decrease sympathetic nervous system output.

image Angiotensin II receptor blockers: Losartan and telmisartan prevent angiotensin II from binding on smooth muscle sites in arteries, promoting vasodilatation.

image Diuretics: Frusemide and hydrochlorothiazide reduce blood volume and decrease vascular resistance.

image Beta blockers: Propranolol and sotolol reduce heart rate, and force of contraction. Selective beta blockers are preferred. Non-selective beta blockers are contra-indicated in patients with asthma, because their beta agonist action is blocked.

image ACE inhibitors: Captopril, ralopril retard renin-angiotensin system leading to vasodialatation.

image Calcium channel blockers: Amlodipine, nifedipine, decrease the calcium influx in smooth and cardiac muscles, reduce total peripheral resistance and decrease force of contraction.

image Alpha blocking agent: Prazosin, terazosin prevent norepinephrine from binding to receptors in arterioles leading to vasodialatation.

Therapeutic goals and pharmacologic strategies for hypertension

Therapeutic goal Pharmacologic strategies
Reduce volume overload Diuretics
Block beta-1 adrenergic receptors Beta-1 adrenergic receptor antagonists
  ACE inhibitors
Dilate blood vessels Angiotensin II receptor antagonists
Reduce sympathetic outflow from the central nervous system Calcium channel blocking agents
  Alpha-1 adrenergic receptor antagonists
  Alpha-2 adrenergic receptor antagonists

Oral side effects of antihypertensive medicines

Drugs Side effects
Diuretics Dry mouth, lichenoid reactions
Beta blockers Dry mouth, lichenoid reactions, taste change
ACE inhibitors Loss of taste, dry mouth, ulcerations, angioedema
Calcium channel blockers Gingival enlargement, dry mouth, altered taste
Alpha blockers Dry mouth
Direct-acting vasodilators Facial flushing possible, increased risk of gingival bleeding and infection
Central-acting agents Dry mouth, taste changes, parotid pain
Angiotensin II antagonists Dry mouth, angioedema, sinusitis, taste loss

Dental considerations

Patients with controlled hypertension can receive dental care in short appointments.

Anxiety and pain should be avoided since endogenous epinephrine release in response to pain or fear may induce dysrhythmias.

Preoperative reassurance and sedation with 10 mg temazepam or 5 mg diazepam may be helpful.

Raising patients from supine position may cause postural hypertension and loss of consciousness if patient is using thiazides, calcium channel blockers.

Aspirating syringe should be used to give local anesthesia to avoid intravenous entry of epinephrine.

Epinephrine in local anesthesia is not contraindicated unless systolic pressure is over 200 mmHg or diastolic pressure is over 115 mmHg.

Epinephrine containing local anesthesia should not be given in large doses in patients taking non-selective beta blockers since interaction may induce hypertension and cardiovascular complications.

Gingival retraction cords containing epinephrine should be avoided.

Administration of two to three cartridges of local anesthesia with epinephrine 1:100,000 will not cause cardiovascular changes.

Epinephrine should be used with caution in patients taking tricyclic antidepressants and diuretics since acute hypertensive changes and dysrhythmias, respectively may occur.

Ischemic or Coronary Heart Disease

It is one of the most common medical problem in general population. Coronary heart disease is an inflammatory disease affecting the large and medium sized arteries of heart resulting in inadequate or decreased coronary blood flow. Atherosclerosis and hypertension are the major contributory factors.

Atherosclerosis basically refers to the formation of fibro-fatty lesions in the walls of arteries. These may increase in size to cause stenosis of the vessels reducing the blood flow to the heart on exercise. This is known as angina. In the later stages, the atherosclerotic plaque ruptures and exposes the arterial blood to the plaque contents and stimulates the formation of hemostatic plug. This occlusive thrombus may cause myocardial infarction.

It is related to a variety of risk factors. Knowledge about the risk factors will help the dentist to assess the risk of cardiac problems in patients with no coronary problems.

Risk factors

Angina Pectoris

It is the most common clinical presentation of ischemic heart disease and is infrequent before the age of 40 years. It may be defined as a temporary inability of the coronary arteries to supply the myocardium with the sufficient amount of circulated blood. Atherosclerotic narrowing of the coronary arteries is an important cause of this imbalance in oxygen supply. It is rarely caused by spasm of the blood vessels. Initially, the atherosclerosis does not lead to any symptoms. However, the obstruction becomes large over a period of decades to cause pain. The pain of angina is described as a sense of choking, tightness, heaviness, or compression of the chest, sometimes radiating to the left arm or jaws. The common precipitating causes include physical exertion and emotions.

Levine’s sign is characteristic of ischemic chest pain. It is seen in angina pectoris and myocardial infarction. This sign described by Dr Sam Levine who observed many of his patients suffering from chest pain hold their fist over the chest.

Dental considerations

Preoperative nitroglycerin can be given prophylactically before dental therapy.

Effective local anesthesia is a must. Long-acting local anesthesia with bupivacaine can be used with vasoconstrictor to prolong the effect of local anesthesia. Aspirating syringe is a must.

Increased heart rate and blood pressure during long appointments indicate need to conclude dental care.

If a person develops angina during dental treatment, the procedure should be terminated and the patient should be seated in semi-inclined position and the patient should be given nitroglycerin 0.3–0.6 mg sublingually. If pain persists even after 3 minutes, additional doses (up to 3 mg) every 5 minutes should be given and medical help should be sought. If pain persists, 300 mg of chewable aspirin is given. Moreover, morphine sulfate (IV) relieves pain and anxiety.

Nausea, bradycardia, hypertension indicating myocardial infarction may occur.

Tricyclic antidepressants are contraindicated. Conscious sedation and general anesthesia should be deferred for 3 months in patients with recent onset angina or unstable angina.

Myocardial Infarction

It is a severe form of coronary artery disease. An anginal pain lasting longer than 30 minutes is considered to be a myocardial infarction. The pain may be accompanied by nausea and vomiting, tachycardia, grossly irregular pulse, pallor and difficulty in breathing, sweating, and restlessness. About 10% have painless infarctions.

Diagnosis

The diagnosis of acute myocardial infarction is based on the presence of two of the following three criteria: (1) signs and symptoms compatible with myocardial ischemia, (2) typical ECG changes—ST segment elevation at the end of the PR segment, (3) measurement of creatinine kinase (CK) and myocardial-bound CK (CK-MB).

Elevations in the serum troponin T and troponin 1 levels, which are sensitive markers for myocardial injury, have also been used to test for acute myocardial infarction.

Therapeutic goals and pharmacologic strategies for coronary heart disease

Therapeutic goals Pharmacological strategies
Inhibit progression of atherosclerosis Lipid-lowering agents
HMG-Co-A reductase inhibitors
Improve circulation in coronary arteries Nitrated calcium channel blockers
Reduce workload Beta-1 adrenergic receptor antagonists
Prevent thrombus formation Antithrombotic agents
Prevent coagulation Anticoagulants

Congenital Heart Disease

It is a common heart disease among children, present in 1% of live births. Congenital defects involving heart or adjacent vessels may be associated with other congenital anomalies. These congenital anomalies can be cyanotic or acyanotic in nature.

Acyanotic

Atrial and ventricular septal defects, patent ductus arteriosus, coarctation of aorta, pulmonary stenosis, mitral valve prolapse, aortic stenosis.

Rheumatic Fever

Rheumatic fever is the most common cause of cardiac valve disorders. The mitral valve is affected more frequently. It results from an altered immunologic response to a group A beta hemolytic streptococcal pharyngitis, leading to formation of Aschoffs nodules in the myocardium which develops 1–3 weeks after the streptococcal infection. Though, only 3% of cases of beta hemolytic pharyngitis resulting in rheumatic disease, there is no way to forecast which individuals will have rheumatic heart disease (RHD).

Common manifestations include new onset murmur, carditis, polyarthritis, chorea, erythema marginatum, fever and subcutaneous nodules (modified Jones criteria). The beta streptococcal infection is confirmed by increased serum antistreptolysin O (ASO) antibody titer or positive throat culture. RHD resulting in valvular injury is confirmed by echocardiography for any patient with a history of rheumatic fever, it is imperative to determine whether the infection resulted in RHD.

Infective (Bacterial) Endocarditis

Infective endocarditis (IE) is a rare, potentially lethal infection, predominantly affecting heart valves. The endocardium can also be affected. It results from bacteremia originating from any site and representing almost any species. It is caused mainly by bacteria as well as fungi.

Bacterial endocarditis can be defined as an infection that affects the endocardium in valvular, mural and septal defects, as well as in arteriovenous and arterioarterial shortcircuits.

It usually occurs in older individuals, peak prevalence is 6th or 7th decade. It is less frequent in the young, except in intravenous drug users. It occurs predominantly in males. Most patients have pre-existing cardiac disease. The mitral valve is more frequently affected followed by aortic valve and tricuspid valve. Sterile vegetations, i.e. comprising of platelets and fibrins accumulate over the damaged valves and these get readily infected during bacteremias resulting in infective endocarditis.

Main groups affected by infective endocarditis Approximate percentage of all cases of infective endocarditis
No obvious cardiac valve disease 40%
Chronic rheumatic heart disease 30%
Congenital heart disease 10%
Prosthetic cardiac valves 10%
Intravenous drug abuse 10%

Oral microorganisms could play an important role in the pathogenesis of infective endocarditis. Some oral microorganisms pass into the blood stream and colonize areas of valvular endothelium on a previous sterile incipient vegetation. Staphylococcus aureus usually produces an acute infection, whereas Streptococcus viridans, enterococci, certain gram-positive and gram-negative bacteria and fungi may produce subacute infection. Dental treatment precedes infective endocarditis only in 5–10% of cases though a number of oral manipulations can cause bacteremia.

It is estimated that the prevalence of bacteremia following scaling and root planing is about (0–25%), with single tooth extraction (25–50%) and almost 50–80% with multiple extractions.

The prevalence of bacteremia is about 25–50% with periodontal surgery.

It has been reported that some cases of infective endocarditis have been associated with oral infections in the absence of dental manipulations and hence a synergistic effect between the presence of periodontal or periapical infections and dental manipulations could favor the development of infective endocarditis.

Moreover, a number of studies have reported that brushing teeth, chewing gum or eating may provoke bacteremia and that the prevalence of IE increases when these acts are performed by patients with intraoral infections.

Because of the high morbidity and mortality associated with IE, antibiotic prophylaxis has been advised. Though, antibiotic therapy has not proven to prevent endocarditis and it also carries with a risk of adverse reactions (anaphylaxis), it is still advised prophylactically for certain treatment procedures.

Clinical Conditions that Warrant Use of Antibiotic Prophylaxis

Patients with compromised immune status

These patients are more prone to develop an overwhelming septicemia from a relatively harmless transient bacteremia because of their compromised immune status.

Patients undergoing chemotherapy are prone to develop infections as the chemotherapeutic agents suppress the inherent immune system. Invasive dental procedures such as extraction of teeth, subgingival scaling and periodontal surgeries that might cause significant bleeding warrant antibiotic prophylaxis in these patients.

Patients inflicted with HIV/AIDS generally do not require antibiotic cover; nevertheless it is always wise to perform dental procedures such as extraction of teeth and periodontal surgeries under antibiotic cover as it might minimize the risk of the patient acquiring a superinfection.

Patients with uncontrolled insulin-dependent diabetes mellitus (IDDM) are vulnerable to infections. Invasive dental procedures that involve significant amount of bleeding may require antibiotic cover.

Jan 12, 2015 | Posted by in Oral and Maxillofacial Radiology | Comments Off on 18: Systemic Disorders and their Clinical Implications
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