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Although treatment benefits from pharmacologic treatment of hypertension are well-established, whether treatment need be lifelong is uncertain. JNCV suggests that reductions in pharmacologic therapy may be attempted after one year of successful control. Since a substantial minority (25%) of patients treated may not have truly elevated BP, but rather suffer "white coat" hypertension, trials of medication withdrawal appear warranted.
Eighteen studies of antihypertensive medication were reviewed, including six studies specifically addressing elderly patients. In an analysis of 12 trials, at one year, 40% of patients remained normotensive; at two years, 28% remained normotensive. Looking at trials involving elderly patients, 26% were normotensive two years after cessation of therapy.
The ability to withdraw antihypertensive medication in about one-fourth of hypertensive patients would be a great economic savings both to the patient and the health care system. Even if only modest blocks of time (1-2 years) are involved, the benefit remains substantial.
Froom J, et al. J Am Board Fam Pract 1997;10:249-258.
Clinical Scenario: The ECG shown in the figure was obtained from a 34-year-old man who complained of atypical chest pain of recent onset. A 12-lead tracing obtained a month earlier was reported to show complete right bundle branch block (RBBB) but no acute changes. Based on this verbal report, do you suspect an interim change during this month? Should this patient be admitted to the hospital?
Interpretation: Several key points should be emphasized from this clinical scenario an accompanying ECG.
1. The significance of the finding of complete right or left bundle branch block depends most on the clinical setting in which the conduction defect occurs. Development of new complete RBBB or LBBB in association with acute infarction is likely to indicate extensive damage, a poorer prognosis, and potential need for cardiac pacing. In contrast, the occurrence of complete RBBB in an otherwise healthy young adult without evidence of underlying heart disease does not necessarily carry adverse prognostic implications.
2. Recognition of ischemia or acute infarction is clearly more difficult in the presence of a conduction defectespecially when there is complete LBBB. However, definite evidence of ischemia or infarction may sometimes be identifiable despite the presence of an underlying conduction defect.
3. The ECG shown in the figure illustrates how acute changes may look when they occur in a patient with an underlying conduction defect. The rhythm in this tracing is sinus arrhythmia. The QRS complex is wide and manifests the typical pattern of complete RBBB (rsR' complex in lead V1: wide terminal S waves in leads I and V6). However, the appearance of the ST segment and T waves is definitely not what one usually expects with uncomplicated RBBB.
The most remarkable abnormality on this tracing is seen in lead III, which manifests deep T wave inversion. ST segment depression is also seen in the other two inferior leads (II and aVF), as well as in leads V5 and V6. A subtle but real change should be noted in the high lateral leads (I and aVL). Specifically, a somewhat widened Q wave is seen in lead aVLand the ST segment in leads I and aVL is coved, slightly elevated, and peaked. This picture is suggestive of a hyperacute ST-T wave change, which is often the first indicator of acute infarction. Not in particular that the appearance of the ST segment and T wave in lead aVL is the virtual "mirror image" reciprocal of the ST-T wave appearance in lead I. It turned out that this 34-year-old man with atypical chest pain was in the process of evolving an extensive acute infarction.