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Biomedical subjects

E H Niggemann

Publications and source records attributed to E H Niggemann.

7 recordsLinked to original sources
PubMed1988

Effect of increasing heart rate on left ventricular performance in patients with normal cardiac function.

The influence of an increase in heart rate on left ventricular (LV) contractile performance was assessed in patients with normal LV function. In 19 patients (3 men, 16 women) ages 55 +/- 9 years (mean +/- standard deviation) with normal global and segmental LV function and normal coronary arteries, LV dP/dt max was measured at baseline heart rate and during atrial pacing at baseline +5, baseline +25 and baseline +45 beats/min. In 10 of the patients, intravascular volume was not altered during pacing and, as a result, echocardiographically measured LV end-diastolic dimension decreased (5.4 +/- 0.4 at baseline vs 4.9 +/- 0.5 cm at baseline +45 beats/min, p less than 0.05). In these patients, LV dP/dt max increased modestly (1,571 +/- 237 at baseline vs 1,760 +/- 199 mm Hg/s at baseline +45 beats/min, p less than 0.05). In the other 9 patients, intravascular volume was expanded rapidly (by saline infusion) during pacing and, as a result, LV end-diastolic dimension was held constant (5.2 +/- 0.6 at baseline vs 5.1 +/- 0.6 cm at baseline +45 beats/min, difference not significant). In these patients, LV dP/dt max increased substantially with pacing (1,505 +/- 228 at baseline vs 2,050 +/- 258 mm Hg/s at baseline +45 beats/min, p less than 0.05). Thus, an increase in heart rate induces a modest increase in LV dP/dt max in patients in whom LV preload (as reflected by end-diastolic dimension) is allowed to decrease; in contrast, it causes a marked increase in LV dP/dt max in those in whom LV preload is maintained constant.

Adult↗
PubMed1987

Detection of intracardiac left-to-right shunting in adults: a prospective analysis of the variability of the standard indocyanine green technique in patients without shunting.

Intracardiac left-to-right shunting may be detected and quantitated by an oximetric analysis of blood from the right-sided cardiac chambers and prominent early recirculation of indocyanine green after it is injected into the central venous circulation and sampled from a systemic artery. Although the variability of oximetric measurements has been established in patients without shunting and a range of normal has been determined for the technique, the variability of the indocyanine green method among persons without shunting has not been clarified; as a result, a range of normal for indocyanine green has not been established. In 66 adult patients in whom hydrogen inhalation (an extremely sensitive technique for detecting even very small intracardiac left-to-right shunts) revealed no shunting, indocyanine green curves were generated by injection into the pulmonary artery as blood was sampled from a systemic artery. In these patients the percentage left-to-right shunt (that is, the percentage of pulmonary blood flow reaching the lungs through an intracardiac shunt) (determined with the equation of Carter et al) ranged from -9% to +26% (+7 +/- 8%, mean +/- standard deviation). There was no definable relation between the percentage left-to-right shunt and the indicator dilution measurement of cardiac output. Thus, these data establish a range of normal for the indocyanine green technique of detecting and measuring intracardiac left-to-right shunting. If this technique is to be used reliably to detect shunting, its results must demonstrate a percentage shunt in excess of +26%.

Adult↗
PubMed1986

Smoking-induced coronary vasoconstriction in patients with atherosclerotic coronary artery disease: evidence for adrenergically mediated alterations in coronary artery tone.

In patients with atherosclerotic coronary artery disease, cigarette smoking increases myocardial oxygen demand but may cause an inappropriate decrease in coronary blood flow and myocardial oxygen supply. This study was performed to explore the mechanism of smoking-induced coronary vasoconstriction and, specifically, to determine if smoking causes an alpha-adrenergically mediated increase in coronary artery tone. In 36 chronic smokers with coronary artery disease (27 men and nine women, 50 +/- 9 [mean +/- SD] years old), heart rate-systolic arterial pressure double product and coronary sinus blood flow (by thermodilution) were measured before and during smoking both before and after (1) normal saline (n = 5, control subjects), (2) an alpha-adrenergic-blocking agent, phentolamine, 5 mg (n = 15), (3) a beta-adrenergic-blocking agent, propranolol, 0.1 mg/kg (n = 12), or (4) sodium nitroprusside, 0.4 to 0.8 micrograms/kg/min, given in a dose sufficient to diminish systolic arterial pressure by 15% (n = 4). During the initial smoking period, rate-pressure product increased and coronary sinus blood flow was unchanged by smoking in all groups. After 30 to 75 min, saline, phentolamine, propranolol, or sodium nitroprusside was given, and measurements were repeated. In the control subjects, rate-pressure product and coronary sinus blood flow responded in a similar manner to that observed previously. In those receiving phentolamine, rate-pressure product was unchanged, but coronary sinus blood flow rose substantially with smoking (percent change +2 +/- 15% during the first smoking period [before phentolamine] and +32 +/- 17% during the second smoking period [after phentolamine]; p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Medical evaluation of sexually abused children: a review of 311 cases.

The case records of 311 children and adolescents who were medically evaluated for sexual abuse are reviewed. Only 18% of these victims were assaulted by strangers; 131 of the assailants were relatives. Thirty percent of the victims reported multiple assaults over a time period of one week to nine years. Physical examination showed no abnormalities in only 23% of the patients. Twenty-one patients had gonorrhea and seven patients were pregnant. Guidelines for the medical evaluation of patients suspected to be victims of sexual abuse are discussed.

Adolescent↗
PubMedDate not supplied

Near-drowning.

It can be seen that the physiologic changes occurring in near-drowning are complex. The pulmonary changes including edema, shunting, and alterations in surfactant properties cause disturbances in oxygenation and acid-base balance which can have severe consequences for the near-drowning victim if immediate and intelligent treatment is not directed toward their correction. Although blood volume, serum electrolyte, and hematologic changes are generally not severe, they must still be considered. The secondary effects, which make up the clinical situation met with in patients eventually admitted to the hospital, may result in disaster in those who appear to have recovered from the acute episode unless careful vigilance is maintained. The possession of a sound knowledge base related to these aspects is essential in the treatment and care of near-drowning victims.

Acid-Base Equilibrium↗