Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

Coronary CT radiation dose reduction strategies at an Australian Tertiary Care Center - improvements in radiation exposure through an evidence-based approach

Introduction

Coronary CT Angiography (CCTA) is a rapidly increasing technique for coronary imaging; however, it exposes patients to ionising radiation. We examined the impact of dose reduction techniques using ECG‐triggering, kVp/mAs reduction and high‐pitch modes on radiation exposure in a large Australian tertiary CCTA service.

Methods

Data on acquisition modes and dose exposure were prospectively collected on all CCTA scans from November 2009 to March 2014 at an Australian tertiary care centre. A dose reduction algorithm was developed using published techniques and implemented with education of medical staff, radiographers and referrers. Associations of CCTA acquisition to radiation over time were analysed with multivariate regression. Specificity in positive CCTA was assessed by correlation with invasive coronary angiography.

Results

3333 CCTAs were analysed. Mean radiation dose decreased from 8.4 mSv to 5.3, 4.4, 3.7, 2.9 and 2.8 mSv (P < 0.001) per year. Patient characteristics were unchanged. Dose reduction strategies using ECG‐triggering, kVp/mAs reduction accounted for 91% of the decrease. High‐pitch scanning reduced dose by an additional 9%. Lower dose was independently related to lower kVp, heart rate, tube current modulation, BMI, prospective triggering and high‐pitch mode (P < 0.01). CCTA specificity remained unchanged despite dose reduction.

Conclusion

Implementation of evidence‐based CCTA dose reduction algorithm and staff education programme resulted in a 67% reduction in radiation exposure, while maintaining diagnostic specificity. This approach is widely applicable to clinical practice for the performance of CCTA.

Quantitation of mitral regurgitation after percutaneous MitraClip repair: comparison of Doppler echocardiography and cardiac magnetic resonance imaging

OBJECTIVE

Percutaneous valve intervention for severe mitral regurgitation (MR) using the MitraClip is a novel technology. Quantitative assessment of residual MR by transthoracic echocardiography (TTE) is challenging, with multiple eccentric jets and artifact from the clips. Cardiovascular magnetic resonance (CMR) is the reference standard for left and right ventricular volumetric assessment. CMR phase-contrast flow imaging has superior reproducibility for quantitation of MR compared to echocardiography. The objective of this study was to establish the feasibility and reproducibility of CMR in quantitating residual MR after MitraClip insertion in a prospective study.

METHODS

Twenty-five patients underwent successful MitraClip insertion. Nine were excluded due to non-magnetic resonance imaging (MRI) compatible implants or arrhythmia, leaving 16 who underwent a comprehensive CMR examination at 1.5 T (Siemens Aera) with multiplanar steady state free precession (SSFP) cine imaging (cine CMR), and phase-contrast flow acquisitions (flow CMR) at the mitral annulus atrial to the MitraClip, and the proximal aorta. Same-day echocardiography was performed with two-dimensional (2D) visualization and Doppler. CMR and echocardiographic data were independently and blindly analyzed by expert readers. Inter-rater comparison was made by concordance correlation coefficient (CCC) with 95% confidence intervals (CIs), and Bland-Altman (BA) methods.

RESULTS

Mean age was 79 years, and mean LVEF was 44%±11% by CMR and 54%±16% by echocardiography. Inter-observer reproducibility of echocardiographic visual categorical grading by expert readers was poor, with a CCC of 0.475 (-0.7, 0.74). Echocardiographic Doppler regurgitant fraction reproducibility was modest (CCC 0.59, 0.15-0.84; BA mean difference -3.7%, -38% to 31%). CMR regurgitant fraction reproducibility was excellent (CCC 0.95, 0.86-0.98; BA mean difference -2.4%, -11.9 to 7.0), with a lower mean difference and narrower limits of agreement compared to echocardiography. Categorical severity grading by CMR using published ranges had good inter-observer agreement (CCC 0.86, 0.62-0.95).

CONCLUSIONS

CMR performs very well in the quantitation of MR after MitraClip insertion, with excellent reproducibility compared to echocardiographic methods. CMR is a useful technique for the comprehensive evaluation of residual regurgitation in patients after MitraClip. Technical limitations exist for both techniques, and quantitation remains a challenge in some patients.

Clinical value of supine and upright myocardial perfusion imaging in obese patients using the D-SPECT camera

PURPOSE

We have assessed whether additional upright imaging increases the confidence of interpretation of stress only supine myocardial perfusion imaging (MPI) in obese patients.

METHODS AND RESULTS

Tc-MIBI stress MPI of 101 consecutive patients (M = 49, 62 ± 12 years) with BMI ≥30 scanned on the D-SPECT cardiac camera were assessed. Images were interpreted as diagnostic or equivocal and the need for a rest study was recorded. Stress supine MPI was interpreted first, then gated and finally upright data were added. Defects on supine but not on upright were defined as artefacts and defects seen on both as abnormal. The total perfusion deficit (TPD) was also quantified. There were 27 normal, 22 abnormal, and 52 equivocal supine scans. The median EF was 52%, unaffecting the need for rest imaging. Upright imaging reclassified 32/52 (62%) equivocal studies as normal and 6/52 (11%) as abnormal (P < 0.001). Rest scan was deemed needed in 74/101 patients on supine vs 42/101 on supine/upright (P < 0.001). Supine TPD was normal in 53 and supine/upright TPD was normal in 70 patients (P < 0.001).

CONCLUSION

Supine stress MPI is inadequate in obese patients. The addition of upright imaging significantly increases the ability to interpret scans as diagnostic and may reduce considerably the need for rest imaging.

Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation

PURPOSE

High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings.

METHODS

The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS ≥3 or coronary territorial SSS ≥2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5% and coronary territorial TPD ≥3% were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; ≥50% was considered significant.

RESULTS

Of the 50 patients, 13 (26%) had no stenosis, 22 (44%) had single-vessel disease, 6 (12%) had double-vessel disease and 9 (18%) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's ρ 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92% (35/38), 83% (10/12) and 90% (45/50) vs. 84% (32/38), 50% (6/12) and 76% (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89% (31/35), 57% (8/14) and 80% (39/49) vs. 86% (31/36), 77% (10/13) and 84% (41/49), respectively.

CONCLUSION

HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual assessment better than conventional SPECT. Further assessment in a larger patient population may be needed to confirm this observation.

Comparison of radiation dose and the effect of operator experience in femoral and radial arterial access for coronary procedures

Radial access coronary procedures are associated with fewer access site complications compared to femoral access. There is controversy regarding greater radiation exposure to patient and operator using radial access. We aimed to compare radiation dose during coronary procedures for the 2 access routes and assess the effect of operator experience with radial access on radiation dose. Fluoroscopy time (FT) and dose-area product (DAP) were recorded for all radial access and femoral access procedures during default femoral access, transition phase (femoral access and early radial access), and default radial access. Femoral access cases (n = 848, 412 diagnostic, 436 percutaneous coronary interventions [PCIs]) and radial access cases (n = 965, 459 diagnostic, 506 PCIs) were assessed. For diagnostics, median FT for radial access was longer than for femoral access (4.43 minutes, interquartile range [IQR] 2.55 to 8.18, vs 2.34 minutes, IQR 1.49 to 4.18, p <0.001) and associated with larger DAP (radial access 1,837 μGy·m(2), IQR 1,172 to 2,783, vs femoral access 1,657 μGy·m(2), IQR 1,064 to 2,376, p <0.001). For PCI, FT was longer for radial access (median 12.02 minutes, IQR 7.57 to 17.54, vs femoral access 9.36 minutes, IQR 6.13 to 14.27, p <0.001)-this did not translate into an increased DAP (femoral access median 3,392 μGy·m(2), IQR 2,139 to 5,193, vs radial access 3,682 μGy·m(2), IQR 2,388 to 5,314, p = NS). For diagnostic radial access, FT decreased from the transition phase (n = 134) to the default radial access phase (n = 323, 5.12 minutes, IQR 3.07 to 9.40, vs 4.21 minutes, IQR 2.49 to 7.52, p = 0.03). This was not observed for PCI. In conclusion, transition from femoral access to radial access for diagnostics and PCI increased FT. DAP increased for diagnostic radial access but not PCI compared with femoral access. FTs for radial access diagnostic cases decreased with experience.

INFLUENCE OF TEMPERATURE AND HYDROGEN ION CONCENTRATION UPON THE SPORE CYCLE OF BACILLUS SUBTILIS

1. At 5 degrees C. no germination took place. 2. At 25 degrees C. and at 37 degrees C. germination occurs if the hydrogen ion concentration of the broth is kept between pH 5 and pH 10, but not at higher or lower pH values. 3. The completion of the spore cycle likewise requires a hydrogen ion concentration between pH 5 and pH 10. 4. The spores can germinate when the pH value is 10, although after germination the vegetative cells multiply only to a very slight extent and soon pass into spores. 5. The slight growth and multiplication of vegetative cells in broth of pH 10 suggest that the formation of endospores in this medium must be caused largely by the unfavorable reaction of the medium rather than by the accumulation of metabolic products. 6. Automatic adjustment of the medium seems to play a rôle in the completion of the spore cycle. 7. The results are not only of theoretical importance but they have a practical application to the preservation of food by canning and by other methods.

Predictors of excess mortality after myocardial infarction in women

BACKGROUND

Research suggests that women have higher mortality after acute myocardial infarction (AMI) than men. Potential factors to explain this disparity include delay to presentation, less aggressive interventional strategies, and more severe disease at coronary angiography in women.

METHODS

Consecutive patients (n=663) presenting to coronary care between Jan 2002 and Jan 2005 with ischemic type chest pain and AMI (troponin T >0.09ng/ml) were recruited. Details of the presentation and management were obtained from the medical notes. The primary endpoint was three month all cause mortality.

RESULTS

Of these patients 31% (205/663) were female. Mean age of women was 70 (SD 11) and 63 (SD 13) for men (p<0.001). There was no difference between the sexes for delay in presentation or treatment or for ST elevation infarction site. Women had prior hypertension more than men (49% 100/205 vs. 38% 174/458, p=0.008). Women were less likely to have diagnostic catheterisation (67% 137/205 vs. 80% 365/458 p<0.001). Both genders had similar coronary artery disease extent and frequencies of LV impairment (EF<45%) and were equally likely to undergo revascularisation (79% 108/137 vs. 81% 295/365 p=NS). There was an excess 3 month mortality among women (11% 23/205 vs. 5% 24/458 in men p=0.006). INDEPENDENT: predictors of 3 month mortality by logistic regression analysis were age (OR 1.06, 95% CI 1.03 -1.09, p<0.001) and LV impairment (OR 0.28, 95% CI 0.13-0.56, p<0.001).

CONCLUSION

As LV impairment was comparable in men and women, the excess mortality identified is due to older age at presentation of women.

ST segment elevation in lead aVR during exercise testing is associated with LAD stenosis

PURPOSE

To evaluate, in patients with chest pain, the diagnostic value of ST elevation (STE) in lead aVR during stress testing prior to (99m) Tc-sestamibi scanning correlating ischaemic territory with angiographic findings.

METHODS

Consecutive patients attending for (99m) Tc-sestamibi myocardial perfusion imaging (MPI) completed a treadmill protocol. Peak exercise ECGs were coded. STE >or=0.05 mV in lead aVR was considered significant. Gated perfusion images and findings at angiography were assessed.

RESULTS

STE in lead aVR occurred in 25% (138/557) of the patients. More patients with STE in aVR had a reversible defect on imaging compared with those who had no STE in aVR (41%, 56/138 vs 27%, 114/419, p=0.003). Defects indicating a left anterior descending artery (LAD) culprit lesion were more common in the STE in aVR group (20%, 27/138 vs 9%, 39/419, p=0.001). There was a trend towards coronary artery stenosis (>70%) in a double vessel distribution involving the LAD in those patients who had STE in aVR compared with those who did not (22%, 8/37 vs 5%, 4/77, p=0.06). Logistic regression analysis demonstrated that STE in aVR (OR 1.36, p=0.233) is not an independent predictor of inducible abnormality when adjusted for STD >0.1 mV (OR 1.69, p=0.026). However, using anterior wall defect as an end-point, STE in aVR (OR 2.77, p=0.008) was a predictor even after adjustment for STD (OR 1.43, p=0.281).

CONCLUSION

STE in lead aVR during exercise does not diagnose more inducible abnormalities than STD alone. However, unlike STD, which is not predictive of a territory of ischaemia, STE in aVR may indicate an anterior wall defect.

Using multimedia virtual patients to enhance the clinical curriculum for medical students

Changes in the environment in which clinical medical education takes place in the United States has profoundly affected the quality of the learning experience. A shift to out-patient based care, minimization of hospitalization time, and shrinking clinical revenues has changed the teaching hospital or "classroom" to a degree that we must develop innovative approaches to medical education. One solution is the Virtual Patient Project. Utilizing state-of-the-art computer-based multimedia technology, we are building a library of simulated patient encounters that will serve to fill some of the educational gaps that the current health care system has created. This project is part of a newly formed and unique organization, the Harvard Medical School-Beth Israel Deaconess Mount Auburn Institute for Education and Research (the Institute), which supports in-house educational design, production, and faculty time to create Virtual Patients. These problem-based clinical cases allow the medical student to evaluate a patient at initial presentation, order diagnostic tests, observe the outcome and obtain context-sensitive feedback through a computer program designed at the Institute. Multimedia technology and authoring programs have reached a level of sophistication to allow content experts (the teaching faculty) to design and create the majority of the program themselves and to allow students to adapt the program to their individual learning needs.

The effect of anonymous vs. nonanonymous rating conditions on patient satisfaction and motivation ratings in a population of substance abuse patients

Patient self-report in evaluations involving alcohol and other drug abuse has generally been found to be reliable and valid. However, little is known about the variables associated with greater or lesser degrees of reliability and validity. This study was conducted to determine how motivation and satisfaction ratings obtained under anonymous conditions would compare with ratings obtained under nonanonymous conditions. Over the course of 12 months, 1397 subjects in the Boston Target Cities Project were assigned to either confidential or fully anonymous data collection procedures in an interrupted time-series design. Anonymity had either no effect on ratings or accounted for < 1% of the variance. Satisfaction and motivation ratings obtained under confidential conditions are probably as reliable and valid as ratings obtained under fully anonymous conditions.

The business of education: a new paradigm

Business as usual is not the answer these days. But how do you create a new paradigm for academic educational and research endeavors? There is increasing pressure to separate the costs of providing care to patients from those of educating students and residents. It is evident already that we will not enjoy the flexibility of the past to cross-subsidize the academic effort. Presented here is a case study--a joint venture between Harvard Medical School and Beth Israel HealthCare created to sustain the academic mission, as distinct from its clinical business, and promote innovation in medical education and research through intellectual leadership, dedicated state-of-the-art facilities, and a focused development effort.

Whatever became of the schizophrenogenic mother?

From the late 1940s to the early 1970s, the concept of the "schizophrenogenic mother" was popular in the psychiatric literature. Research later confirmed that the mother who could cause schizophrenia in her offspring did not exist. Such a blame-levelling concept, which had no basis in scientific fact, may have caused a great deal of harm. Sociocultural factors, coupled with developments in psychiatric theory, contributed to the genesis of the concept. Implications of this episode in the history of psychiatry are discussed.

The impact of fine-needle aspiration biopsy on a diagnostic electron microscopy laboratory

We retrospectively reviewed the number and types of diagnostic electron microscopic specimens from a 4 1/2-year period. During this period, the number of fine-needle aspirate biopsy specimens processed increased in a linear fashion, from a relatively uncommon occurrence to the current level of activity, in which fine-needle aspiration specimens now represent 40% to 50% of the nonrenal diagnostic material examined by electron microscopy. This study documents the increasing importance of fine-needle aspirate-type specimens in the everyday operation of a diagnostic electron microscopy facility.

Nonamyloidotic fibrillary glomerulopathy

We describe a 28-year-old woman with nonamyloidotic fibrillary glomerulopathy. She had modest but stable renal insufficiency over a ten-year period, nephrotic-range proteinuria, sarcoidosis, and seven of the 25 signs of Down's syndrome. The rarity of the co-occurrence of these conditions suggests that they are not etiologically linked.

Captopril-associated acute interstitial nephritis

A 57-year-old male with mild impairment of renal function secondary to diabetic glomerulosclerosis developed acute renal failure (creatinine 32.4 mg/dl) associated with a generalized desquamative skin rash and peripheral eosinophilia shortly after initiation of antihypertensive therapy with captopril. An acute interstitial nephritis was demonstrated on renal biopsy, and improvement was temporally related to initiation of therapy with prednisone. A review of the literature revealed 5 similar cases in whom acute deterioration of renal function occurred following initiation of captopril and in whom there were features of a hypersensitivity reaction, including skin rash, fever, eosinophilia, azotemia, eosinophiluria, and a Coombs-positive hemolytic anemia. Renal biopsy, where available, revealed an acute interstitial nephritis. Observations from these cases suggest that, of the angiotensin-converting enzyme inhibitors, this syndrome appears to be specific for captopril, begins within the 1st month of therapy, is not dose-dependent, and generally resolves on cessation of therapy. Steroids may hasten recovery, but sufficient data are not available to confirm their efficacy.

Hydrosyringomyelia and its management in childhood

Syringomyelia, once regarded as a degenerative disease of adults, is now recognized to be a disorder usually associated with the Chiari malformation and occurring in patients of all ages. We have reviewed 47 patients with syringomyelia treated on the Neurosurgical Service at the Hospital for Sick Children during the years 1977 to 1985. Twelve of these patients had a Chiari I malformation, 30 had a Chiari II malformation, and 5 had an acquired Chiari malformation. Thirty-one of these patients were treated by decompression of the Chiari malformation and plugging of the obex, 5 were treated by a simple posterior fossa decompression, 9 were treated by shunting of the syringomyelic cavity, and 2 were treated by a combined decompression of the posterior fossa and shunting of the syrinx. The Gardner procedure (decompression of the Chiari malformation and plugging of the obex) was the procedure most commonly used in managing our group of patients and resulted in improvement in over 70% of patients.

Mediation of the discriminative stimulus properties of 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) by the putative 5-HT1A receptor

Male Sprague-Dawley rats were trained to discriminate the putative 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) from saline in a 2-lever operant drug discrimination paradigm. The 8-OH-DPAT cue was found to be highly selective; neither the 5-HT receptor agonists, quipazine, LSD, MK 212 and RU 24969, the 5-HT releasing agent, p-chloroamphetamine, nor the alpha 2-adrenoceptor agonist, clonidine, were able to substitute for 8-OH-DPAT in tests of generalization. In contrast, both buspirone and TVX Q 7821, which like 8-OH-DPAT have high affinity and selectivity for the 5-HT1A recognition site, generalized to the 8-OH-DPAT cue in a dose-dependent manner. The discriminative stimulus properties of 8-OH-DPAT were not antagonized by the 5-HT2 receptor antagonist, ketanserin, or the selective beta 1- and beta 2-adrenoceptor antagonists, betaxolol and ICI 118.551, indicating that neither 5-HT2 receptors, nor beta-adrenoceptors play a significant role in the behaviour. However, the 8-OH-DPAT cue was antagonized stereoselectively by pindolol and alprenolol, which have relatively high affinity and stereoselectivity for 5-HT1, but not 5-HT2, recognition sites. Similarly, the capacity of TVX Q 7821 to generalize to the 8-OH-DPAT cue could be blocked by pindolol. In view of the fact that 8-OH-DPAT has negligible affinity for the 5-HT1B site, the above results are consistent with its discriminative stimulus properties being mediated by the putative 5-HT1A receptor. Moreover, agonist activity at central 5-HT1A receptors may be an important mechanism contributing to the anxiolytic properties of buspirone and TVX Q 7821.

Pharmacological analysis of the behavioural and thermoregulatory effects of the putative 5-HT1 receptor agonist, RU 24969, in the rat

The roles of recognition sites for central neurotransmitters in the mediation of the behavioural effects of the putative 5-hydroxytryptamine (5-HT1) receptor agonist, RU 24969 [5-methoxy-3(1,2,3,6-tetrahydropyridin-4-yl)1H indole] in the rat have been examined. The drug RU 24969 was found to have high affinity for 5-HT1A and 5-HT1B recognition sites. Hyperlocomotion, induced by RU 24969, was enhanced in animals depleted of 5-HT with 5,7-dihydroxytryptamine, suggesting an involvement of 5-HT receptors in the mediation of this behaviour. However, results of experiments with 5-HT receptor antagonists argued against the receptors being of either the 5-HT1 or 5-HT2 type. Despite the negligible affinity of RU 24969 for catecholamine receptors, hyperlocomotion induced by RU 24969 was clearly dependent on intact catecholamine systems. When hyperlocomotion was blocked by treatment with reserpine, reciprocal forepaw-treading and a flat body posture, behavioural responses which are consistent with activation of the putative 5-HT1A receptor, became evident. When animals were restrained from moving, RU 24969 dose-dependently reduced body temperature, an effect that may also be associated with activation of the 5-HT1A recognition site. Thus, although the mechanism by which RU 24969 induces hyperlocomotion is not yet established, the agonist nevertheless can induce functional responses consistent with its high affinity for the 5-HT1A recognition site.

Group B streptococcal colonisation and the outcome of pregnancy

Vaginal colonisation of pregnant women with group B streptococci (GBS) was not related to age, parity or blood group. There were marked differences between racial groups, Asians having a low colonisation rate and Negroes a high rate. Vaginal GBS colonisation was associated with intrapartum pyrexia, but not with preterm labour, premature rupture of membranes or other complications in labour. Group B streptococci may be an important cause of bacteriuria in pregnancy and their effect on the outcome of pregnancy as urinary pathogens needs further evaluation.

Is group B streptococcal screening during pregnancy justified?

Twenty-eight per cent of women investigated during pregnancy were carriers of group B streptococci (GBS). The use of broth enrichment was the most significant factor in determining GBS carriage rates. GBS carriage decreased during pregnancy. Transmission of GBS from mother to baby was related to vaginal carriage but rectal carriage in pregnancy was the best predictor of maternal carriage at term. Rectal and vaginal swabs taken at 28 and 36 weeks correctly predicted 92% of intrapartum GBS carriage. Although accurate prediction of intrapartum GBS carriage is possible, mass screening for GBS in pregnancy is unlikely to be cost-effective in those countries with a low incidence of neonatal GBS sepsis.

Disruption in the temporal sequence of regional ventricular contraction. I. Characteristics and incidence in coronary artery disease

While spatial asynergy at end-systole has been well characterized in patients with coronary artery disease, assessment of regional asynchrony has been hampered by technical constraints. We developed a computer-assisted method for analyzing regional asynchrony from the equilibrium (ECG-gated) radionuclide ventriculogram. Twenty patients with normal contrast left ventriculograms (nine with a normal coronary arteriogram [group 1] and 11 with coronary artery disease [group 2]) and 20 patients with asynergy during contrast ventriculography (group 3) were studied. The earliest evidence of regional asynchrony occurred in early systole. Regional ejection fraction at one-third systole was 0.32 +/- 0.02 (mean +/- SEM) in group 1, 0.22 +/- 0.01 in group 2 (p less than 0.001) and 0.12 +/- 0.01 in asynergic regions in group 3 patients (p less than 0.001). In group 3, severe forms of regional asynchrony appeared in both early systole and early diastole: five patients (25%) had early systolic paradox, 13 (65%) had regional prolongation of peak ejection fraction and 16 (80%) had reduced percent peak ejection fraction at global end-systole. It appears, therefore, that there is progressively increasing regional asynchrony in patients with increasing severity of coronary artery disease.

Regional left ventricular function in acute myocardial infarction: evaluation with quantitative radionuclide ventriculography

Regional and global left ventricular performance was noninvasively assessed with quantitative gated equilibrium radionuclide ventriculography in 43 patients an average of 40 hours after the onset of a first acute transmural myocardial infarction. In all 16 patients with anterior infarction, regional ejection fraction, a quantitative measure of regional left ventricular performance, was uniformly depressed in the infarcted zone. In patients with inferior infarction the abnormalities of regional performance were less severe. Fourteen of 20 patients (70 percent) with inferior infarction had depressed performance in the infarcted zone. Function in noninfarcted zones was abnormal in only 6 of the 20 patients (30 percent) with inferior infarction, but it was abnormal in 11 of the 16 patients (69 percent) with anterior infarction, particularly in those with severe pump failure. As a consequence, global left ventricular ejection fraction was significantly lower in patients with anterior than in those with inferior infarction (mean +/- standard error of the mean 31 +/- 3 percent versus 51 +/- 3 percent, less than 0.005). Prognosis and clinical functional class were related to performance not only in infarcted zones, but also in noninfarcted zones as assessed with electrocardiography. It is concluded that depressed function in apparently noninfarcted left ventricular zones contributes significantly to left ventricular dysfunction after acute myocardial infarction, particularly in patients with anterior infarction.

The paradox image: a noninvasive index of regional left-ventricular dyskinesis

The paradox image, a functional image of regional dyskinesis derived from the equilibrium (gated) radionuclide ventriculogram, was constructed by subtracting the background-corrected end-diastolic frame from the background-corrected end-systolic frame. In 11 patients showing dyskinesis by contract ventriculography, the percentage of left-ventricular picture elements containing paradox ranged from 3.6 to 55.6% (21.44% +/- 4.45 s.e.m.). In 11 patients with normokinesis and in eight patients with hypokinesis by contract ventriculography, the left-ventricular picture elements demonstrating paradox were less than 1.1% in all cases. In nine patients with akinesis, the percentage of left-ventricular picture elements containing paradox was 2.05% +/- 0.96 s.e.m. and was less tha 2% in seven patients. There was also an excellent agreement between the location of dyskinesis on the paradox image and that by contrast ventriculography. The paradox image is a sensitive indicator of left-ventricular dyskinesis and should be useful in the evaluation of patients with suspected left-ventricular asynergy.