Morphology of ectopic ventricular beats and their relationship to ventricular tachycardia in acute myocardial ischemia

The features of ventricular arrhythmia in coronary spasm induced by ergonovine were examined to elucidate the characteristics of ventricular arrhythmia in acute myocardial ischemia. The coupling intervals and configurations of the QRS wave of the premature ventricular beats (PVBs) were extremely variable, even in the same individual and at the closer time phases. The prematurity index (R-R'/QT) of PVBs with the right bundle branch block (RBBB) pattern was significantly smaller than with the left bundle branch block (LBBB) pattern. The vulnerability index (R-RX QT/R-R') of PVBs with the RBBB pattern was significantly larger than with the LBBB pattern. The incidence of PVBs with the RBBB pattern (50.4%) was slightly larger than with the LBBB pattern (40.5%). PVBs deteriorated into ventricular tachycardias (VTs) in 29 (24.8%) of 117 cases with the RBBB pattern and in 11 (11.7%) out of 94 cases with the LBBB pattern. Thus, PVBs with the RBBB pattern were more likely to progress to VT than with the LBBB pattern. But it is difficult to assess the clinical significance of PVBs from their QRS morphology alone, because 11 (27.5%) of 40 cases of VT were initiated by PVBs with the LBBB pattern.

Analysis of current source of the heart using isomagnetic and vector arrow maps

Vector arrow maps and isomagnetic maps were constructed with a second derivative SQUID (superconducting quantum interference device) gradiometer in normal subjects and in various pathological conditions to study the inverse problem of electromotive forces and to determine whether the magnetocardiogram (MCG) provides different information from the electrocardiogram (ECG). The current sources deduced from these maps corresponded well with the activation sequences in normal and pathologic conditions reported previously. As second derivative gradiometer measures of the spatial differentiation of the magnetic field, these maps reflected well the current sources close to the anterior chest, namely the right ventricle and right atrium. In addition, it was possible to better localize the sources with this detector than with the ECG or first order gradiometer, suggesting that the isomagnetic and vector arrow maps obtained with the second derivative gradiometer were useful for solving the inverse problem. The MCG also provided different information from the ECG, so use of the MCG in addition to the ECG might be helpful in determining current sources more accurately.

Brain catecholamines in spontaneously hypertensive and DOCA-salt hypertensive rats

The concentrations and alpha-methyl-p-tyrosine (alpha-MPT) induced disappearance of catecholamines, adrenaline, noradrenaline and dopamine, were measured in selected areas of the brainstem and hypothalamus of spontaneously hypertensive rats (SHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. The catecholamine levels were measured by a sensitive radioenzymatic assay method combined with microdissection of the rat brain. The adrenaline concentration was higher in the area A1 of young SHR, but not in adult SHR, than in age-matched control rats. Noradrenaline concentrations and the alpha-MPT induced noradrenaline disappearance were less in the rostral part of the nucleus tractus solitarii (NTS) and the nucleus hypothalamic anterior of young SHR, and in the rostral part of the NTS of adult SHR. On the other hand in DOCA-salt hypertensive rats, the concentrations of adrenaline and noradrenaline were the same as in control rats in the examined areas. The alpha-MPT induced noradrenaline disappearance was less in the rostral part of the NTS of DOCA-salt hypertensive rats. Dopamine concentrations and the alpha-MPT induced dopamine disappearance were the same in the examined areas of SHR and DOCA-salt hypertensive rats. The results suggest that SHR have a change in adrenergic neural activity in the brainstem and a decrease in noradrenergic neural activity in the brainstem and hypothalamus while DOCA-salt hypertensive rats have a decrease in noradrenergic neural activity in the brainstem. Such changes in brain catecholaminergic neurons may have played an important role in the development of hypertension in these rats.

Corticotropin-releasing factor (CRF)-like immunoreactivity in the adrenal medulla

Bovine adrenal medulla extract prepared by acid-acetone or acid methanol extraction showed two peaks of CRF-like immunoreactivity on Sephadex G-50 chromatography. One eluted near the void volume and another (low molecular weight CRF-like immunoreactivity) eluted slightly before arginine vasopressin (AVP), while most of the immunoreactivity in bovine hypothalamus coeluted with synthetic ovine CRF. When low molecular weight CRF fractions were chromatographed by reversed phase high performance liquid chromatography, three CRF-like immunoreactive peaks appeared. The first peak appeared near TRH, the second one eluted near AVP and the last one eluted near somatostatin. These three peaks of immunoreactivity showed ACTH releasing bioactivity in rat pituitary cells cultures. Therefore, the adrenal medulla-CRF-like substances might be tissue-CRF which may play a role to stimulate ACTH release in the severe stress conditions.

Magnetocardiograms of patients with left ventricular overloading recorded with a second-derivative SQUID gradiometer

Magnetocardiograms (MCGs) were recorded by means of a second-derivative SQUID (superconducting quantum interference device) magnetometer in 60 normal subjects and 95 patients with left ventricular overloading to determine the clinical value of the MCG. In patients with left ventricular overloading, the Q or S wave was increased in the upper anterior part of the thorax, and the R wave was increased in the left lower part of the thorax, indicating increased leftward force due to left ventricular overloading. For detection of left ventricular hypertrophy or dilatation from echocardiographic measurements, the sensitivity and specificity of the MCG were similar to those of the standard ECG, or slightly better. In patients with left ventricular systolic overloading, the Q wave was decreased in the lower anterior part of the thorax, indicating a decreased septal vector. Inversion of the T wave was seen more frequently in the MCGs than in the ECGs of patients with left ventricular overloading, suggesting that the MCG is useful for detecting early abnormalities of repolarization. These results suggest that the MCG may provide information that is difficult to obtain from the standard 12-lead ECG.

Vector U loop in normal and hypertensive subjects

The U loops of vectorcardiograms (VCG) were recorded in 100 normal subjects and 123 subjects with hypertension, using a direct-writing vectorcardiograph with memory function. These U loops were examined qualitatively and quantitatively. Subjects with hypertension were classified into four groups on the basis of electrocardiographic findings, and the correlation between findings on the U loop and the severity of hypertension was studied. The U loop of normal subjects was directed similarly to the T loop, showing either an arc or semilunar shape in the horizontal plane. In hypertensive subjects the U loop tended to be displaced anteroinferiorly and to the right with an increase in severity of hypertension. In these subjects the U loop was of slightly greater amplitude than in normal subjects, and was long and slender in shape. Anterior and rightward displacement of the U loop was also observed in hypertensive cases who showed no abnormality in the T wave of standard lead ECGs or in the T loop of the VCG. These findings seem useful as clinical parameters of the hemodynamic state in the early stage of hypertension. Based on these results, it was hypothesized that mechanical factors, such as stretch of the ventricular muscles induced by pressure loading of the left ventricle, may contribute greatly to genesis of the U loop.

Corticotropin releasing factor (CRF)-like immunoreactivity in the hypothalamus and posterior pituitary of the goat, bovine, rat, monkey and human

Goat hypothalamic extract prepared by HCl extraction and chromatographed on a Sephadex G-50 column showed two immunoreactive CRF peaks. Most of the immunoreactivity coeluted with synthetic ovine CRF, and a small peak eluted near the void volume. Bovine, monkey, rat and human hypothalamic extracts prepared by acid-acetone or acid-methanol extraction showed three immunoreactive peaks. Most of the immunoreactivity coeluted with ovine CRF, and other smaller peaks eluted near the void volume and slightly before arginine vasopressin. Goat hypothalamic extract showed the highest cross-reactivity with anti-ovine CRF serum, followed by bovine hypothalamic extract. Less cross-reactivity was found in human, rat and monkey hypothalamic extracts. CRF immunoreactivity in goat hypothalamic extract coeluted with ovine CRF on reversed phase high performance liquid chromatography (HPLC) and main CRF immunoreactivity in human and rat hypothalamic extracts eluted slightly later than ovine CRF. These results suggest that there is a heterogeneity among the CRF molecules in these species and that goat CRF may be more similar to that of sheep CRF and the amino acid sequence or molecular weight of other animals CRF may be different from that of sheep CRF. The monkey posterior pituitary and rat neurointermediate lobe showed similar elution patterns of CRF immunoreactivity to their hypothalamic extracts on Sephadex gel filtration and HPLC. These results indicate that the posterior pituitary contains a similar CRF to hypothalamic CRF.

A new pulse sequence for "fast recovery" fast-scan NMR imaging

This paper describes the "fast recovery" (FR) method for fast NMR imaging. The FR method combines a sequence of four RF pulses-alternating selective 90 degrees nutation pulses and nonselective 180 degrees pulses-with a gradient field pulse sequence which includes "spoiler" pulses to destroy the coherence between successive sequence cycles. We use the 2-D backprojection method of image reconstruction, but other imaging methods could be applied. The paper analyzes the behavior of the macroscopic magnetization-compares the FR method with other methods and proposes "figure of merit" expressions for relative signal-to-noise (S/N) ratios, scan time reduction ratios, and image contrast-and presents experimental results, including backprojection image reconstruction 2-D images and computed T1 and T2 images. For the FR method, in theory and practice, we find that, after each scan sequence cycle, magnetization is restored to equilibrium quickly and exactly; scan time can consequently be less than a tenth that for the saturation recovery method without any penalty in signal-to-noise ratio. Image contrast is even higher than that of the SR method, and compromise "optimum" sequence (interpulse timing) parameters give high image contrast for a wide range of tissue T1 and T2 (spin-lattice and spin-spin relaxation time) values.

[Case of primary double lung cancer in the same lobe]

In a 70-year-old male complaining chiefly of cough and expectoration, an abnormal shadow was detected in the left upper lobe by chest X-ray. Therefore, he was admitted for further examination. A tumorous shadow, 5 X 4.5 X 2.5 cm was noted; it corresponded to S1 + 2b on the left side. Left upper lobectomy was performed. Histologic findings of the excised lung were giant cell cancer in the tumorous part, and squamous epithelial cancer at the cut end of the bronchus, i.e. the cut end of the left upper bronchi. This is a rare case with primary double cancer in the same lobe.

Free nail bed graft for treatment of nail bed injuries of the hand

Free full-thickness grafts of nail bed of the lesser toes or an amputated fingertip were successfully performed on 11 fingers of 10 patients since 1979. In nine patients in whom the nail beds had been severely crushed or lost, but the nail matrix was intact, the end results of this technique were excellent. In one patient in whom both the nail bed and matrix had been lost, free grafting of the toenail bed and matrix was performed, with a good result. The procedure can be used when restoring the length of the tip in fingertip amputation if used in combination with local skin flaps such as V-Y advancement or local rotation flaps.