Fall In Arterial Pressure Research Articles

Long-lasting Hypotensive Effect in Renal Hypertensive Rats Induced by Nitric Oxide Released From a Ruthenium Complex

In this study, we investigated the effect of the ruthenium complex [Ru(terpy)(bdq)NO] (TERPY) on the arterial pressure from renal hypertensive 2 kidney-1 clip (2K-1C) rats, which was compared with sodium nitroprusside (SNP). The most interesting finding was that the intravenous bolus injection of TERPY (2.5, 5.0, 7 mg/kg) had a dose-dependent hypotensive effect only in 2K-1C rats. On the other hand, SNP (35 and 70 μg/kg) presented a similar hypotensive effect in both normotensive (2K) and 2K-1C although the effect of 70 μg/kg was >35 μg/kg. The injection of the nonselective NO-synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) increased the arterial pressure in 2K and 2K-1C rats with a similar magnitude. After infusion of L-NAME, the hypotensive effect induced by TERPY and SNP was potentiated in both 2K and in 2K-1C rats. The administration of the superoxide scavenger 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl increased the hypotensive effect induced by TERPY or SNP in both 2K and 2K-1C rats. The hypotensive effect induced by TERPY was longer than that produced by SNP. Taken together, our results show that the TERPY has a long-lasting hypotensive effect, which has a dose dependence and higher magnitude in 2K-1C compared with in 2K rats. In comparison with SNP, TERPY is less potent in inducing arterial pressure fall, but it presents a much longer hypotensive effect.

Cardio-respiratory effects of systemic neurotensin injection are mediated through activation of neurotensin NTS1 receptors

The purpose of our study was to determine the cardio-respiratory pattern exerted by the systemic injection of neurotensin, contribution of neurotensin NTS1 receptors and the neural pathways mediating the responses. The effects of an intravenous injection (i.v.) of neurotensin were investigated in anaesthetized, spontaneously breathing rats in following experimental schemes: (i) control animals before and after midcervical vagotomy; (ii) in three separate subgroups of rats: neurally intact, vagotomized at supranodosal level and initially midcervically vagotomized exposed to section of the carotid sinus nerves (CSNs); (iii) in the intact rats 2 minutes after blockade of neurotensin NTS1 receptors with SR 142948. Intravenous injection of 10μg/kg of neurotensin in the intact rats evoked prompt increase in the respiratory rate followed by a prolonged slowing down coupled with augmented tidal volume. Midcervical vagotomy precluded the effects of neurotensin on the frequency of breathing, while CSNs section reduced the increase in tidal volume. In all the neural states neurotensin caused significant fall in mean arterial blood pressure preceded by prompt hypertensive response. The cardio-respiratory effects of neurotensin were blocked by pre-treatment with NTS1 receptor antagonist. The results of this study showed that neurotensin acting through NTS1 receptors augments the tidal component of the breathing pattern in a large portion via carotid body afferentation whereas the respiratory timing response to neurotensin depends entirely on the intact midcervical vagi. Blood pressure effects evoked by an intravenous neurotensin occur outside vagal and CSNs pathways and might result from activation of the peripheral vascular NTS1 receptors.

A meta-analysis of intraoperative factors associated with postoperative cardiac complications

Background: Preoperative cardiac risk is commonly determined with the help of risk scores and risk stratification tools. This predetermined cardiac risk may be profoundly changed by intraoperative surgical events. This meta-analysis aimed to identify intraoperative factors that independently predict postoperative cardiac complications in the presence of preoperative cardiac risk factors. Method: A PubMed Central search was conducted from January 1966 to June 2010, to identify independent intraoperative predictors of postoperative cardiac complications in observational perioperative studies and randomised controlled trials which controlled for preoperative cardiac risk factors. Results: Eleven studies were identified for inclusion in this meta-analysis. Intraoperative blood transfusion [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.8-3.4] was the only independent intraoperative risk predictor identified in more than one study. Other identified independent intraoperative factors included a > 20 mmHg fall in mean arterial blood pressure for > 60 minutes (OR 3.0, 95% CI 1.8-4.9), > 30% increase in baseline systolic pressure (OR 8.0, 95% CI 1.3-50), tachycardia in the recovery room (> 30 beats per minute from baseline for > 5 minutes) (OR 7, 95% 1.9-26), new onset atrial fibrillation (OR 6.6, 95% CI 2.5-20), hypothermia (OR 2.2, 95% CI 1.1-5) and remote ischaemic preconditioning (OR 0.22, 95% CI 0.070.67). None of these studies controlled for blood transfusion. Conclusion: Both surgical and haemodynamic intraoperative events significantly increased the risk of postoperative cardiac complications. Intraoperative blood transfusion has the strongest evidence that supports this finding. It is possible that modification of these intraoperative risk factors by anaesthetists and surgeons might reduce postoperative cardiac events.

Observational study of choice of anaesthesia and outcome in patients with severe pre-eclampsia who present for emergency Caesarean section

Objectives: Recent evidence in the literature suggests that regional anaesthesia may be the preferred choice over general anaesthesia for patients with severe pre-eclampsia who present for a Caesarean section. This study was conducted to determine if this applied to our population and to assess outcomes.Design: A retrospective comparative observational study was conducted.Setting and subjects: The study was carried out at the King Edward VIII Hospital and included patients with severe pre-eclampsia who presented for emergency Caesarean section. Eighty-four charts were analysed.Outcome measures: The type of anaesthetic that was administered was determined and compared for maternal intraoperative haemodynamic changes and maternal and neonatal outcomes.Results: Sixty-nine per cent of patients received spinal anaesthesia and 25% general anaesthesia (GA). Intraoperative systolic blood pressures of < 100 mmHg were recorded in 19% of GA and in 27.6% of spinal anaesthesia cases. A > 20% fall in mean arterial pressure from baseline was noted in 66.7% of GA and in 75.9% of spinal anaesthesia cases. There was no maternal mortality and one case of morbidity (a spinal anaesthesia case). An Apgar score of < 7 was recorded in 66.7% of GA cases and in 19% of spinal anaesthesia cases. Neonatal morbidity and mortality occurred in 33.3% of GA and in 10.3% of spinal anaesthesia cases.Conclusion: Maternal morbidity and mortality were not significantly different between the two groups. Neonatal outcomes were poorer in the GA group, but neonates in the GA group had significantly lower birthweights and gestational ages. Their mothers also had more severe disease. This study supports spinal anaesthesia as an appropriate anaesthetic choice in patients with severe pre-eclampsia.

Hemodynamic changes in lipid emulsion therapy (SMOFlipid) for bupivacaine toxicity in swines

To evaluate the hemodynamic changes following SMOFlipid emulsion therapy with after bupivacaine intoxication in swines. Large White pigs were anesthetized with thiopental, tracheal intubation was performed and mechanical ventilation was instituted. Hemodynamic variables were recorded with invasive pressure monitoring and pulmonary artery catheterization (Swan-Ganz catheter). After a 30-minute resting period, 5 mg.kg(-1) of bupivacaine by intravenous injection was administered and new hemodynamic measures were performed 1 minute later; the animals were than randomly divided into two groups and received 4 ml.kg(-1) of saline solution or 4 ml.kg(-1) of SMOFlipid emulsion 20%. Hemodynamic changes were then re-evaluated at 5, 10, 15, 20 and 30 minutes. Bupivacaine intoxication caused fall in arterial blood pressure, cardiac index, ventricular systolic work index mainly and no important changes in vascular resistances. SMOFlipid emulsion therapy was able to improve blood pressure mainly by increasing vascular resistance since the cardiac index had no significant improvement in our study. Hemodynamic results of the use of lipid emulsion in bupivacaine intoxication were better than the control group. The SMOFlipid emulsion is a option for reversing hypotension in cases of intoxication by bupivacaine.

When filling the glass only leaves it half empty!– Insight into the cardiovascular physiology of haemorrhage under heat stress

When filling the glass only leaves it half empty!– Insight into the cardiovascular physiology of haemorrhage under heat stress

Perioperative effect of epidural dexmedetomidine with intrathecal bupivacaine on haemodynamic parameters and quality of analgesia

Background: The present study was a randomised controlled trial designed to evaluate the perioperative effect of epidural dexmedetomidine, in conjunction with intrathecal bupivacaine.Method: In this trial, 60 male patients of American Society of Anesthesiologists' grades I and II, between 20–50 years of age, and posted for elective lower limb orthopaedic surgery, were selected. After written informed consent was obtained and a thorough preanaesthetic check-up carried out, the patients were randomly divided into two groups using the manual envelope randomisation technique. Group I received 2.5 ml of 0.5% bupivacaine intrathecally, plus 10 ml normal saline (NS) epidurally (control). Group II received 2.5 ml of 0.5% bupivacaine intrathecally, plus 2.0 μg/kg dexmedetomidine epidurally, made up to 10 ml with NS (study).Results: We observed a significant prolongation in the duration of analgesia to 424.1 minutes (Group II) in patients receiving epidural dexmedetomidine, in comparison to 140.0 minutes in patients receiving saline (Group I). There was a significant fall in the pulse rate and mean arterial pressure five minutes following epidural dexmedetomidine in Group II patients, which lasted throughout the study period. The majority of the patients in Group II were sedated, yet arousable, by verbal commands or light tactile stimulus (sedation scale 3–4) 10 ± 5 minutes following administration of dexmedetomidine in the epidural space. This decrease in the level of consciousness lasted for 45 ± 5 minutes.Conclusion: The addition of 2 μg/kg dexmedetomidine epidurally to 2.5 ml of intrathecal bupivacaine prolongs the duration of analgesia, and decreases the requirement of rescue analgesics in patients undergoing lower-limb orthopaedic surgery, with a significant fall in pulse rate and mean arterial pressure.

Blood pressure lowering effect of Tylophora hirsuta wall

Crude hydromethanolic extract of Tylophora hirsuta (Th.Cr) was studied in spontaneous hypertensive Wistar rats for possible effects on high blood pressure and heart rate. In the absence of atropine, fall in arterial blood pressure was 64±7 mmHg at the dose of 100 mg/kg while in the presence of atropine, there was no effect on arterial blood pressure suggesting cholinergic receptor blockade. Fall in heart rate, in the absence of atropine, was 218±8 beats per minute (BPM) while, fall in heart rate, in the presence of atropine was 110±5.6 BPM, indicating that the action is through cholinergic muscarinic receptors as atropine is a typical anticholinergic drug. The percent fall in blood pressure and heart rate were standardized versus acetylcholine; standard cholinergic drug. Th.Cr tested mildly positive for alkaloids, flavonoids and strongly positive for terpenes and terpenoids, and saponins. α- Amyrin acetate was isolated from the n-hexane fraction of Th.Cr for the first time from T. hirsuta. The results confirm the presence of acetylcholine like substances in T. hirsuta that provide a basis for its traditional use in treatment of hypertension. The action may be attributed to the phytochemicals like flavonoids, saponins, terpenes and terpenoids and α- amyrin acetate isolated for the first time from the plant.

Microvascular Dilatation after Haemodialysis Is Determined by the Volume of Fluid Removed and Fall in Mean Arterial Pressure

Background/Aims: The effects of haemodialysis on the microcirculation are poorly understood. This study examined the changes in small vessel calibre. Methods: 24 patients (including 12 males, median age 62.5 years, range 30–87) underwent digital retinal photography immediately before and after routine haemodialysis. Arteriolar and venular calibres were measured from the images by a trained grader using a highly reproducible, computer-assisted method. Results: Patients had an average 2.0 ± 0.3 litres of fluid removed with dialysis, and their mean arterial blood pressure fell by 6.8 mm Hg (CI 13.8–0.2, p = 0.06). Retinal arteriole calibre did not change (mean difference 2.3 µm, CI –1.1 to 5.7, p = 0.17) but the venules dilated (mean difference 12.7 µm, CI 7.3–18.3, p < 0.001). Calibre returned to baseline by 2 h. Venules dilated less in diabetics than non-diabetics (mean difference –6.2 µm, CI –9.6 to –2.9, p < 0.01). Retinal venular dilatation correlated positively with the volume of fluid removed per kilogramme body weight (5.9, CI 0.2–11.5, p = 0.04), and negatively with the fall in mean arterial pressure (–0.36, CI –0.72 to –0.01, p < 0.05) after adjusting for age, gender, diabetes and dyslipidaemia. Conclusion: Haemodialysis is associated with systemic venular dilatation.

Induction for classic laryngeal mask airway insertion: Does low-dose fentanyl work?

Background:Laryngeal mask airway (LMA) insertion requires an optimal balance of anesthesia. Propofol with different opioids is a preferred combination. Two doses of fentanyl were compared for the efficacy and side effects.Materials and Methods:96 patients were randomly distributed into F1 (fentanyl 1 mcg/kg) and F2 (fentanyl 2 mcg/kg) groups. The conditions for LMA insertion, hemodynamic profile, bronchoscopic view, and incidence of sore throat were compared.Result:There was no statistically significant difference in any parameter in the two groups except for a significant fall in systolic and mean arterial pressure in F2 group.Conclusion:Both doses of fentanyl (1 and 2 mcg/kg) provide comparable insertion conditions for LMA. Fentanyl in the lower dose provides a more stable hemodynamic profile.

Simulation of Exercise-Induced Syncope in a Heart Model with Severe Aortic Valve Stenosis

Severe aortic valve stenosis (AVS) can cause an exercise-induced reflex syncope (RS). The precise mechanism of this syncope is not known. The changes in hemodynamics are variable, including arrhythmias and myocardial ischemia, and one of the few consistent changes is a sudden fall in systemic and pulmonary arterial pressures (suggesting a reduced vascular resistance) followed by a decline in heart rate. The contribution of the cardioinhibitory and vasodepressor components of the RS to hemodynamics was evaluated by a computer model. This lumped-parameter computer simulation was based on equivalent electronic circuits (EECs) that reflect the hemodynamic conditions of a heart with severe AVS and a concomitantly decreased contractility as a long-term detrimental consequence of compensatory left ventricular hypertrophy. In addition, the EECs model simulated the resetting of the sympathetic nervous tone in the heart and systemic circuit during exercise and exercise-induced syncope, the fluctuating intra-thoracic pressure during respiration, and the passive relaxation of ventricle during diastole. The results of this simulation were consistent with the published case reports of exertional syncope in patients with AVS. The value of the EEC model is its ability to quantify the effect of a selective and gradable change in heart rate, ventricular contractility, or systemic vascular resistance on the hemodynamics during an exertional syncope in patients with severe AVS.

Study of the novel non-xanthine heterocyclic compound GU285 as a potent non-selective adenosine receptor antagonist in the rat.

The novel pyrazolo[3,4-d]pyrimidine compound GU285 (4-amino-6-alpha-carbamoylethylthio-1- phenylpyrazolo[3,4-d]pyrimidine, CAS 134896-40-5) was examined for its ability (1) to inhibit binding of adenosine (ADO) receptor ligands in rat brain membranes, (2) to antagonise functional responses to ADO agonists in rat right and left atria and coronary resistance vessels, and (3) to reduce the fall in heart rate and arterial blood pressure produced by the ADO A1 agonist N6-cyclopentyladenosine (CPA) in the intact, anaesthetized rat. GU285 competitively inhibited binding of the ADO A1 agonist [3H]-R-N6-phenylisopropyladenosine (R-PIA) yielding a Ki value of 11 (7-18) nmol.l-1 (geometric mean +/- 95% Cl). When assayed against the ADO A2A selective agonist [3H]-2-[p-(2-carboxyethyl)- phenethylamino]-5'-N-ethylcarboxamidoadenosine, (CGS21680), a Ki of 15 (10-24) nmol.l-1 was obtained. In spontaneously beating right atria, GU285 competitively antagonized negative chronotropic effects of R-PIA with a pA2 of 8.7 +/- 0.3 and in electrically paced left atria, GU285 competitively antagonized negative inotropic effects of R-PIA with a pA2 of 9.0 +/- 0.1. In the potassium-arrested, perfused rat heart GU285 (1 mumol.l-1) antagonized only the high sensitivity, ADO A2B mediated component of the biphasic relaxation of the coronary vasculature produced by NECA. The low sensitivity component was unchanged. GU285 (1 mumol.kg-1) antagonized the negative chronotropic and hypotensive effects of the adenosine A1 agonist CPA in anaesthetized rats, producing a 10-fold rightward shift in the dose-response relationship. These data demonstrate that in the rat, GU285 is a potent, non-selective adenosine receptor antagonist that maintains its activity in vivo.

Blood Pressure Lowering Effect of the Extract of Aerial Parts of Capparis aphylla is Mediated Through Endothelium-Dependent and Independent Mechanisms

This investigation was aimed to provide pharmacological evidences for the medicinal use of Capparis aphylla in hypertension. In normotensive anesthetized rats, intravenous administration of the crude extract of Capparis aphylla (Ca.Cr; 3–100 mg/kg) caused a fall in mean arterial pressure (MAP), which was partially blocked in the presence of atropine (2 mg/kg). In isolated rabbit aortic rings, Ca.Cr inhibited phenylephrine (1 μM) and high K+ (80 mM) precontractions with respective EC50 values of 0.10 (0.07–0.15) and 1.22 mg/mL (1.00–1.50), suggesting calcium channel blocking (CCB) activity with a predominant inhibitory effect on receptor operated Ca2+ channels. Pretreatment of the arotic rings with Ca.Cr (0.1–1 mg/mL) caused a rightward shift in the Ca2+ concentration response curves, similar to verapamil. In isolated rat aorta preparations, Ca.Cr caused a partial endothelium-dependent L-NAME/atropine-sensitive vasodilator effect. In guinea-pig atria, Ca.Cr suppressed both rate and force of spontaneous atrial contractions with respective EC50 values of 1.35 (1.01–1.79) and 1.60 mg/mL (1.18–2.17), which remained unchanged in the presence of atropine (1 μM). These data indicate that the blood pressure (BP) lowering effect of the crude extract of Capparis aphylla is mediated through a vasodilator and cardiac depressant effect. The vasodilator effect is partly mediated by an endothelium-dependent, atropine-sensitive NO pathway, while the CCB effect is partly responsible for endothelium-independent vasodilatation and also for the cardiac depressant effect; thus, this study provides pharmacologic evidence with respect to the medicinal use of the plant in hypertension.

Theoretical Analysis of the Effect of Positioning on Hemodynamic Stability During Pregnancy

A left lateral tilt of 15° has been advocated during trauma resuscitation of near-term pregnant patients to avoid the potential for hemodynamic compromise caused by aortocaval compression in the supine position. This recommendation is supported by limited objective evidence, and an experimental determination of the optimal tilt required would be very difficult to accomplish logistically. A derivation of the Guyton/Coleman/Summers computer model of cardiovascular physiology was used to analyze the theoretically expected hemodynamic responses to varying degrees of lateral tilt for a normal pregnancy and during a simulated hemorrhagic shock. Computer simulation studies were used to predict the degree of left lateral tilt required to restore hemodynamic normalcy during the final 20 weeks of gestation. The analytic procedure involved recreating the clinical conditions for a virtual subject through a simulated reenactment of the clinical transfer of a pregnant patient from a lateral to a supine positioning. An analysis of model validity in the context of this particular clinical condition found the model predictions to be within 5% to 12% of experimental results. During the simulated lateral to supine position transfer, the virtual patient with Class I hemorrhage had a 7% greater fall in cardiac output and a 17% greater fall in mean arterial pressure (MAP) than the corresponding nonhemorrhagic patient. The model suggests that 15° of tilt will result in hemodynamic normalization only up to 26 weeks of gestation. In addition, 13% greater tilt is required to achieve hemodynamic normalcy in the hemorrhaged term pregnant patient. Current trauma guidelines suggest that the pregnant trauma patient be placed in a 15° left lateral tilt position to prevent aortocaval compression. A computer simulation study suggests that this tilt may be inadequate to offload the vena cava and normalize the circulation.

Switching control of sympathetic activity from forebrain to hindbrain in chronic dehydration

We investigated the mechanisms responsible for increased blood pressure and sympathetic nerve activity (SNA) caused by 2-3 days dehydration (DH) both in vivo and in situ preparations. In euhydrated (EH) rats, systemic application of the AT(1) receptor antagonist Losartan and subsequent pre-collicular transection (to remove the hypothalamus) significantly reduced thoracic (t)SNA. In contrast, in DH rats, Losartan, followed by pre-collicular and pontine transections, failed to reduce tSNA, whereas transection at the medulla-spinal cord junction massively reduced tSNA. In DH but not EH rats, selective inhibition of the commissural nucleus tractus solitarii (cNTS) significantly reduced tSNA. Comparable data were obtained in both in situ and in vivo (anaesthetized/conscious) rats and suggest that following chronic dehydration, the control of tSNA transfers from supra-brainstem structures (e.g. hypothalamus) to the medulla oblongata, particularly the cNTS. As microarray analysis revealed up-regulation of AP1 transcription factor JunD in the dehydrated cNTS, we tested the hypothesis that AP1 transcription factor activity is responsible for dehydration-induced functional plasticity. When AP1 activity was blocked in the cNTS using a viral vector expressing a dominant negative FosB, cNTS inactivation was ineffective. However, tSNA was decreased after pre-collicular transection, a response similar to that seen in EH rats. Thus, the dehydration-induced switch in control of tSNA from hypothalamus to cNTS seems to be mediated via activation of AP1 transcription factors in the cNTS. If AP1 activity is blocked in the cNTS during dehydration, sympathetic activity control reverts back to forebrain regions. This unique reciprocating neural structure-switching plasticity between brain centres emphasizes the multiple mechanisms available for the adaptive response to dehydration.

Home-made fenestrated amplatzer occluder for atrial septal defect and pulmonary arterial hypertension

We report the management of a patient with secundum atrial septal defect (ASD) and severe pulmonary hypertension. A 65-year-old male with recently diagnosed atrial septal defect was referred to our centre for decompensated right heart failure with rest and exercise induced dispnea and severe pulmonary hypertension. Right heart catheterization confirmed a mean pulmonary pressure of about 55 mmHg and a Qp/Qs of 2.7. An occlusion test with a compliant large balloon demonstrated partial fall of pulmonary arterial pressure. The implantation of a home-made fenestrated Amplatzer ASD Occluder (ASO) was planned in order to decrease left-to-right shunt and promote further decrease of pulmonary arterial pressure in the long-term. Thus, by means of mechanical intracardiac echocardiography study with a 9F 9 MHz UltraIce catheter (Boston Scientific Corp.), we selected a 34 mm ASO for implantation. Four millimeter fenestration was made inflating a 4 mm non-compliant coronary balloon throughout the waist of the ASO, which was successfully implanted under intracardiac echocardiography. After six months, a decrease of pulmonary arterial pressure to 24 mmHg and full compensated right heart failure was observed on transthoracic echocardiography and clinical examination. This case suggests that transcatheter closure with home-made fenestrated ASD in elderly patients with severe pulmonary hypertension is feasible.

L29. Pathophysiology and treatment of hypertension in women in the different phases of life

as a class, they are well tolerated and exhibit a low sideeffect profile. In recent years, CCBs have found their way in obstetrics and gynecology, especially in the management of hypertensive disorders of pregnancy and preterm labor. The lack of adequate data had created uncertainty about the safety of CCBs in pregnancy. Teratogenicity with these agents has been demonstrated in animals, but no cases of possible human malformation or deformity have been reported. Data from human studies suggest that CCBs may cause a clinically insignificant fall in maternal mean arterial pressure, but have little to no effect on uterine perfusion. In many countries, CCBs remain unlicensed for use in pregnancy and it is unlikely the manufacturers will ever apply for this status to change. In case of such off-label prescription, prenatal counseling is mandatory, particularly even when the risk of malformations is above that of the baseline risk. Counselling should include thebackgroundhumanbaseline risk formajormalformations,whether the fetus is at increased risk,whichanomaly has been associated with the agent in question, a risk assessment, methods of prenatal detection, when available, limitations in our knowledge, and limitations of prenatal diagnostic capabilities. Additional aspects include the potential risk of the medical condition for which a drug is prescribed, known interactions (in both directions) between the disease state and the pregnancy andpreventivemeasures, when applicable. The reported differences in pregnancy outcomes for others side effects in women treated with CCBs may be not surprising because the treatment effect is superimposed to maternal diseases associated to higher maternal and perinatal morbidity and mortality, such as hypertension disorders or preterm labor. In a critical view the safety of CCBs in pregnancy may be underestimated since they are not even licensed in most countries for that use, despite this class of drugs is widely administered in practice and reported in literature. At present, it is recommended that a drug only be used during pregnancy if the potential benefit outweighs any potential risk to the fetus. We do believe that this is the situation of CCBs for those critical secondand third-trimester conditions such as Gestational hypertension, Preeclampsia, HELLP syndrome and preterm labor.

Systemic blood pressure profile correlates with cardiac 123I-MIBG uptake in patients with Parkinson's disease

To examine the correlation between the systemic blood pressure profile and cardiac 123I-metaiodobenzylguanidine (MIBG) uptake in patients with Parkinson's disease (PD), we monitored circadian blood pressure patterns of 37 PD patients of 49 to 85years of age (mean, 71.8±8.4years) using a portable blood pressure monitoring device. The duration of PD was 0.5 to 15years, and the disability level (modified Hoehn and Yahr stage) ranged from 1.0 to 4.0 (mean, 2.7±0.7). There were 37 age- and sex-matched control subjects. Cardiac MIBG scintigraphy was performed for the 37 PD patients. Based on the nocturnal fall in mean arterial blood pressure (MABP), we classified patients into extreme dippers (nocturnal reduction of MABP >20%), dippers (>10% but <20%), nondippers (<10% but >0%), and inverted dippers (<0%). Average 24-hour MABP values revealed reduced BP variability in PD patients. The percentage nocturnal fall in MABP was significantly different between PD patients and control subjects (p<0.05). Significant correlations were found between % MABP reduction and the heart-to-mediastinum (H/M) ratio on early and delayed images (p<0.01). The UPDR motor score, early and delay H/M ratios were also significantly different between patients who were and were not dippers (p<0.05). The present results reported for the first time a significant correlation between the systemic blood pressure profile and cardiac 123I-MIBG uptake in patients with PD. The degeneration between the brainstem and the postganglionic neurons of myocardial sympathetic nerves may progress in parallel in patients with PD.

Maternal small arterial elasticity decreases with gestation in normal pregnancy

Changes in maternal blood pressure are seen in normal pregnancy. Mean arterial pressure falls until the end of the second trimester and then rises again to prepregnancy levels in the...

What Is Really a Nonobstructive Hypertrophic Cardiomyopathy? The Importance of Orthostatic Factor in Exercise Echocardiography

The authors report the case of a 23-year-old girl with nonobstructive hypertrophic cardiomyopathy evaluated by resting echocardiography. The patient complained of syncope after playing basketball. The patient was submitted to treadmill exercise echocardiogram, and she exercised for 9 minutes in standard Bruce protocol. The left ventricular outflow gradient did not occur at peak workload; however she developed intraventricular gradient greater than 100 mmHg after exercise in orthostatic position. There was fall in arterial pressure, and the patient was then put in supine position. The authors suggest the possible role of exercise stress echo in symptomatic patients with no significant gradient at baseline, as well as maintenance in orthostatic position after exercise, as an important stress factor. This can disclose the occurrence of left ventricular outflow tract obstruction that should not be detected in other way and has potential relevance in the patient's symptoms understanding.