A new method for recording a three-lead electrocardiogram using a two-channel Holter system

A technique for recording a three-lead electrocardiogram (ECG) without increasing the number of channels and electrodes in a commercially available two-channel Holter recorder was devised. On channel 1, a V5-like lead (CM5 lead) was recorded for 24 consecutive hours. On channel 2, the device could switch continuously between a V2-like lead (CM2 lead) and a II- or III- or a VF-like lead (CMf lead) every 30 sec. Fifty eight patients with angina pectoris were studied using this new device. There were 2 patients with variant angina pectoris, one of whom showed ST elevation in the CM2 lead coupled with ST depression in the CMf lead and the other ST elevation in the CMf lead coupled with ST depression in the CM2 lead. The number of patients having ST depression confined to the CM5 lead only, CM2 lead only and CMf lead only was 17, 2 and 3, respectively. In 41 patients, 127 transient episodes of ischemic type ST changes were observed during daily activity. Only 35 (28%) of these episodes were associated with anginal symptoms and the remaining 92 episodes occurred unrelated to such symptoms. Accordingly, 3-lead Holter monitoring using this device is useful, particularly for the detection of variant angina, and makes it less likely for asymptomatic ischemic ST changes to be overlooked as compared to the 2-lead conventional Holter monitoring system.     

Left internal mammary-to-left circumflex coronary artery collateral pathway in a patient with occluded left circumflex artery

A unique case of left internal mammary artery-to-circumflex coronary artery collateral pathway, which was conceivably encouraged to develop by coronary occlusion. The pathway provided sufficient collateral perfusion to preserve the local myocardial performance.     

Computerised method for recording platelet density distribution

Abstract: In the present study a computerized apparatus was employed for scanning light transmission variations along test tubes containing density-separated platelets. The device consists of a stepping motor, a stationary halogen lamp and a photopotentiometer connected to a personal computer. Anticoagulated whole blood was layered on a preformed continuous Percoll gradient having a density span from 1090 kg/l (bottom) to 1040 kg/l (top). After centrifugation at 3400g for 1.5 hours, high-density cells (i.e. erythrocytes) pass through to the bottom of the test tube and the lighter platelets remain in the gradient. The test tube is moved by the computer between the halogen lamp and the photopotentiometer. Transmission variations along the gradient were recorded and registered in the computer. Density markers beads were used as an internal standard and platelet peak density was determined. After perforating the test tube the gradient was divided into 45 aliquots. In all fractions determination of platelet counts and mean platelet volume was carried out. In addition, in the aliquots having a platelet count > 20 × 10¹²/l the ratio β-thromboglobulin per platelet was also determined. The platelet distribution in the gradient was illustrated graphically. A good agreement was found when comparing platelet distributions in the gradients and light transmission variations along the test tubes.     

A new method for the recording of heart sounds

We have presented a new type of recording apparatus which possesses distortion simulating that of the human ear. This permits strict correlation between clinical cardiology and phonocardiographic records. In addition we have established an even base line which permits accurate timing of the beginning and end of heart sounds. The fundamental characteristics of the first and second sounds are described.