Holley M. Dey

Assessment of the daily blood pressure load as a determinant of cardiac function in patients with mild-to-moderate hypertension

The distribution of blood pressure (BP) values over the day and night was assessed in a group of 30 never previously treated patients with mild-to-moderate essential hypertension via 24-hour ambulatory BP monitoring. Elevated BP values during the awake hours (greater than 140/90 mm Hg) and sleeping hours (greater than 120/80 mm Hg) were used to calculate the total percentage of abnormal BP values (load) in each patient. The relationship between BP load and several indexes of hypertensive cardiac target organ involvement was compared to the relationships among office (casual), 24-hour average BP values, and cardiac indexes. Casual systolic and diastolic BP values did not correlate with left ventricular mass index, left atrial index, or peak left ventricular filling rate. Both 24-hour average BP and systolic and diastolic BP loads correlated with all indexes of cardiac target organ involvement. The BP loads were related to left ventricular mass index and left atrial index more strongly than were the mean 24-hour BP values; however, they were equally correlated for peak left ventricular filling rate. If greater than 40% of the ambulatory BP values were elevated, the likelihood of increased mass or decreased filling was greater than 61%, whereas if less than 40% of the BP values were elevated, the incidence of an abnormal cardiac test result decreased to less than 17%. These data show that the percentage of elevated BP values that includes both the awake and asleep periods is predictive of cardiac target organ involvement in patients with mild-to-moderate hypertension. Patients with mild hypertension who have more than 40% abnormal BP values should strongly be considered for antihypertensive therapy.

Diagnosis of Pedal Osteomyelitis with Tc-99m HMPAO Labeled Leukocytes

The diagnosis of pedal osteomyelitis is often complicated by the presence of pre-existing bony abnormalities. In this study, the utility of radiolabeled white blood cell imaging for the detection of complicated pedal osteomyelitis was evaluated. Twenty-seven men and women were prospectively enrolled and underwent plain film radiography, three-phase bone scan, and Tc-99m hexamethylpropylamine oxine white blood cell scintigraphy of their feet. The presence or absence of osteomyelitis was confirmed in all subjects by microbiologic and histopatholigic analysis of resected bone tissue. The results indicated that white blood cell imaging was more sensitive (90%) and specific (86%) for infection than either bone scan (75% sensitive, 29% specific) or plain film radiography (55% sensitive, 57% specific). This preliminary study suggests that Tc-99m hexamethylpropylamine oxine-labeled white blood cell scintigraphy is a simple, accurate test for the detection of pedal osteomyelitis.

Effects of age and 24-hour ambulatory blood pressure on rapid left ventricular filling

To determine the associations of age, blood pressure (BP) and cardiac structure with left ventricular (LV) diastolic performance, 47 subjects (21 normotensives and 26 age-matched, previously untreated hypertensives) were studied by 24-hour ambulatory BP monitoring, radionuclide ventriculography and sector-guided M-mode echocardiography. Normotension was defined as an awake ambulatory BP less than 130/80 mm Hg and hypertension as an awake ambulatory BP greater than 135/85 mm Hg. Univariate analyses revealed strong negative correlations of LV filling rate with age (r = -0.67, p less than 0.001), 24-hour systolic or diastolic BP (r = -0.59 for systolic BP and -0.57 for diastolic BP, p less than 0.001 for both) and a modest positive correlation with LV ejection fraction (r = 0.42, p less than 0.05). After multivariate analysis, significant dependencies of both the left atrial index and LV mass index on ambulatory BP were found, which negated the significance of the relation of these 2 cardiac structural variables with LV filling rate. The final regression equation predicted LV filling rate from age, BP and LV ejection fraction. Age was the most important single correlate of LV filling, as evidenced by the 14 of 16 subjects (88%) over the age of 53 years (8 hypertensives, 6 normotensives) who had reduced LV filling rates compared with only 9 of the remaining 31 subjects (29%, all hypertensives) under the age of 53 years with reduced LV filling rates. These data demonstrate that LV filling rate is more dependent upon age and BP than left atrial or LV size.(ABSTRACT TRUNCATED AT 250 WORDS)

Reverse redistribution on planar thallium scintigraphy: relationship to resting thallium uptake and long-term outcome.

Reverse redistribution (RR) of thallium-201 has been associated with both acute and healed myocardial infarction, and with recent thrombolysis. The physiologic basis for RR in coronary artery disease (CAD) is unclear but may be related to an admixture of viable and scarred myocardium within the RR segment. We performed thallium reinjection imaging at rest to better characterize RR defects in patients with chronic CAD. We found enhanced uptake of201Tl in 52% of RR segments after reinjection, consistent with significant regional viability that was not evident on redistribution images. We then used a logistic multiple regression analysis to determine whether RR alone or in combination with other scintigraphic findings could predict patient outcome. The results showed that severe RR was an independent predictor of patient outcome. We conclude that RR may have prognostic significance in chronic CAD.

Radionuclide evaluation of doxorubicin cardiotoxicity: the need for cautious interpretation.

Serial radionuclide angiography is a sensitive technique for the identification of asymptomatic cardiac dysfunction secondary to doxorubicin hydrochloride chemotherapy. However, the results of serial studies must be interpreted with caution in order to avoid labeling variations in the left ventricular ejection fraction (LVEF) due to artifact as doxorubicin cardiotoxicity. The use of sequential gated cardiac studies in the evaluation of a thirteen-year-old boy on doxorubicin hydrochloride is presented. Reassessment of the results of these studies showed that technical and biologic factors were the cause of recurring fluctuations in the LVEF, rather than drug toxicity.

Radiogallium hot spleen in Trousseau's syndrome with splenic vein occlusion.

A 75-year-old man had multiple findings that indicated thromboembolic disease. A radiocolloid study showed splenic defects. The remainder of the spleen was hot on radiogallium imaging. The patient had Trousseaus syndrome (tumor-associated thromboembolism) due to carcinoma of the pancreas. The splenic vein was obstructed. Vascular compromise should be considered in the differential diagnosis of the radiogallium hot spleen.

Detection of tricuspid insufficiency by portable nuclear probe monitoring over the liver.

A case is presented in which a portable nuclear scintillation probe was used to detect tricuspid regurgitation. An electrocardiographically–gated scintigraphic collection obtained over the liver was correlated with findings from contrast echocardiography and jugular venous pulse tracings. The nuclear probe may provide a simple means for the detection of tricuspid insufficiency. It remains to be determined if quantification of severity will be possible.

Rapid left ventricular filling is more dependent on age and twenty-four-hour blood pressure than on cardiac size

The associations of age, blood pressure and cardiac structure with rapid left ventricular filling were assessed in 47 subjects (21 normotensives and 26 age-matched untreated hypertensives) by 24-h ambulatory blood pressure monitoring, sector-guided M-mode echocardiography and radionuclide ventriculography. Univariate analyses revealed strong negative correlations of the left ventricular filling rate with age, and 24-h systolic and diastolic blood pressure, and a moderate positive correlation with the left ventricular ejection fraction at rest. Multiple regression analysis was performed with these variables, left atrial size and left ventricular mass index. Left atrial size and the left ventricular mass index were dependent on 24-h blood pressure, indicating that these two cardiac structural variables were less important than left ventricular filling. Age was undoubtedly the most important correlate of left ventricular filling, since 88% of the subjects over 53 years of age had reduced left ventricular filling rates regardless of the blood pressure status. However, under the age of 53 years, only the hypertensives had reduced filling rates. Thus, our study shows that the left ventricular filling rate is more dependent on age and 24-h blood pressure than on the left ventricular mass index. Furthermore, in patients over 53 years of age, it is not possible to separate the effects of hypertension on the diastolic function of the heart from the physiological alterations associated with ageing.