22: 70-year-old male with new-onset unilateral weakness Flashcards
Due to this risk, the United States Preventive Services Task Force recommends:
ALL adults >18 yrs be screened for hypertension
Adults > 20 yrs should be screened for hyperlipidemia if at increased risk for CAD (i.e., diabetic, hypertensive, premature personal history of atherosclerosis or family history of CAD in males < 50 yrs or females < 60 yrs)
All adults be asked about tobacco use, and all smokers be given tobacco cessation interventions.
Clinicians should discuss aspirin chemoprevention with all men over 45 for primary prevention of myocardial infarction.
Orthostasis
A reduction of systolic or diastolic blood pressure of at least 20 or 10 mmHg respectively, measured three minutes after a patient who has accommodated to the supine position assumes a standing or sitting position.
Some experts also consider the test to be positive when the pulse rate remains increased by 20 beats per minute or more (16 beats per minute in the elderly).
afib
is rapid, irregular, and chaotic atrial activity without definable p waves on electrocardiogram. Its presence should be suspected in individuals presenting with dizziness, syncope, dyspnea, or palpitations. While palpation of an irregular pulse or auscultation of an irregular heart rate may raise suspicion of atrial fibrillation, the diagnosis requires confirmation with electrocardiogram.
afib epi
Atrial fibrillation (AF) is the most common arrhythmia physicians face in clinical practice, accounting for about one- third of hospitalizations for arrhythmia. The prevalence of AF increases with age and the severity of congestive heart failure or valvular heart disease. Furthermore, in most cases, AF is associated with the cardiovascular diseases of hypertension, coronary artery disease, cardiomyopathy, and mitral valve disease. Pulmonary disorders of COPD, obstructive sleep apnea, and pulmonary embolism are associated and predisposing factors. Other associated conditions include surgery, excess alcohol intake, hyperthyroidism, and febrile illnesses.
Distinguishing persistent vs. paroxysmal afib
Atrial fibrillation less than 72 hours total duration would be classified as new onset. Chronic atrial fibrillation may be either persistent or paroxysmal. In the paroxysmal form, atrial fibrillation may recur and then revert back to normal rhythm spontaneously, with variable periods of normal sinus rhythm between episodes. The presence of normal rhythm does not rule out the existence of paroxysmal atrial fibrillation. This arrhythmia can occur episodically without clinical detection or significant symptoms for several months.
Cardiovascular or Cerebrovascular Mechanisms:
1.Embolic
Most commonly from the heart or carotid artery– arrhythmias may produce emboli from mural thrombi, atrial appendages, or from diseased heart valves
2.Thrombotic
Native clot within the intracranial vasculature – 85% of strokes are caused by vascular occlusion (thrombotic)
3.Cardiogenic
Secondary to a decrease in cerebral perfusion caused by decreased cardiac output (e.g.: anginal event associated with coronary artery disease), severe hypotension, or hypoxemia related to severe anemia or poor oxygen saturation
4.Hemorrhagic
Secondary to pathologic cerebrovascular changes within the brain attributable to aging, smoking, hypertension, and hyperlipidemia.
Hematologic and Vascular Mechanisms:
Hematologic:
Hyperviscosity or myleoproliferative syndromes (polycythemia, leukemias, or thrombocytosis), vascular obstruction (sickle cell anemia), severe anemia and conditions associated with hypercoagulable states (lupus anticoagulant or antiphospholipid antibody; presence of Factor V Leiden; or deficiencies of protein C, protein S, or antithrombin III).
Vascular mechanisms:
Hypertension leading to thrombosis or bleeding, atherosclerotic emboli from carotid or vertebral plaques, extrinsic compression of cranial vessels (cervical osteophytes, or rotational kinking, tumor), vasospasm (migraine, cocaine) and vasculitis.
TIA Symptoms Preceding Stroke
Individuals experiencing TIA symptoms have been shown to have an 8% to 12% chance of having a stroke within one week and an 11% to 15% chance of having a stroke within one month.
Evaluation of a Patient with Suspected Ischemic Stroke
Time is crucial in evaluation of a patient with suspected ischemic stroke because if given within three hours, intravenous t-PA has proven benefit in salvaging hypoxic brain tissue. Intra-arterial therapy improves functional outcomes if it can be given within six hours.
Although it is desirable to know the results of these tests before giving recombinant tissue Plasminogen Activator (rtPA), thrombolytic therapy should not be delayed while awaiting the results unless:
- there is clinical suspicion of a bleeding abnormality or thrombocytopenia
- the patient has received heparin or warfarin
- use of anticoagulants is not known
AF with Rapid Ventricular Response (RVR) is the presence of physiologic or non-physiologic (electrical) ventricular tachycardia in the presence of AF.
Etiology
Fever, myocarditis, pericarditis, volume contraction, thyrotoxicosis, endogenous catecholamines, and AV nodal dysfunction are causative.
Complications
In the presence of a diminished cardiac output at baseline, AF with RVR predisposes to hemodynamic instability, functional impairment, heart failure and ischemia.
Treatment
»Rate control: Controlling the heart rate with intravenous diltiazem, beta-blockers, or verapamil improves
blood flow and does not delay immediate need for emergency stroke treatment.
»Rhythm control: Cardioversion either via electric shock to the heart with the patient under sedation or via medications given orally or intravenously. Both methods carry a risk of stroke which is greatest in patients who have had atrial fibrillation for more than 48 hours, or who have not been given three weeks of prior anticoagulant therapy.
Symptoms of Right Parietal Infarct
Right-hand dominant patients with strokes in the area of the brain are likely also to have left hemiplegia. Patients with right middle cerebral infarcts affecting the right parietal hemisphere may have difficulties with their spatial and perceptual abilities, which causes them to misjudge distances, or they may attempt to read holding books upside down. They may ignore people or objects in their left visual field or not pay attention to that area of the room. They may also not recognize their functional impairments (denial of stroke disability).
Stroke Symptoms of Other Regions:
Strokes that occur in the brain stem would likely be the cause of respiratory impairment and affect vital functions of blood pressure, heartbeat and consciousness.
Expressive and receptive aphasia and right facial weakness are classically associated with a left middle cerebral artery stroke.
A central nerve injury such as a stroke often spares involvement of the portion of the facial nerve that controls the forehead. This is because there is bilateral central control of this portion of the facial nerve.
A peripheral injury to the facial nerve (such as Bell’s Palsy) causes facial weakness of the forehead.
Basic activities of daily living (BADLs)
Bathing Dressing and undressing Eating Transferring from bed to chair, and back Voluntarily control urinary and fecal discharge Using the toilet Walking (not bedridden)
Instrumental activities of daily living (IADLs) are not necessary for fundamental functioning, but enable the individual to live independently within a community
Light housework Preparing meals Taking medications Shopping for groceries or clothes Using the telephone Managing money
Coronary Heart Disease and Stroke in African Americans
African Americans have the highest rates of coronary heart disease (CHD) of any ethnic group in America, and stroke mortality rates are strikingly high in this population group in general.
