An aid for taking precordial electrocardiograms

AN

AID

FOR

TAKING JOSEPH

PRECORDIAL

ELECTROCARDIOGRAMS

E. F.

RISEMAN,

BOSTON,

MASS.

M.D.

T

HE long rubber belt usually supplied with electrocardiographs for taking precordial leads gives satisfactory results but is somewhat awkward to use. It is common practice, therefore, to dispense with this belt and have either the patient or the operator hold the exploring electrode in place. Because of unavoidable motion, however, this frequently results in some wandering of the baseline or other artifacts. The chest strap described in this communication combines simplicity and accuracy for taking precordial leads with the patient in the recumbent position. The apparatus consists of two parts: (1) a transparent plastic strap weighted at both ends, which rests on the patient’s chest and serves to hold the electrode in place; and (2) a transparent plastic block which replaces the usual electrode handle. The chest strap is made of vinylite or similar flexible transparent plastic about 0.04 inch thick, 20 to 21 inches long, and 3 inches wide (Fig. 1). The vinylite used* was supplied in sheets roughly 18 by 48 inches in size, so that tweIve strips 3 by 24 to 25 inches were obtained from each sheet. Two weights, each between 2 and 3 ounces, are prepared. Brass plate about 2 1; 2 inches x 1 l/2 inches x l/8 inch is satisfactory. One is placed about 2 inches from each end of the plastic strap, the free ends are folded over and sealed so as to enclose these weights. Sealing can be done best by “electronic welding,“t but hand or machine stitching is satisfactory. No serviceable adhesive was found. The plastic bEock can be made from Lucite or Plexiglass rod 1 inch to 1% inches in diameter, cut about s inch thick and polished for transparency, A hole is drilled in one of the flat surfaces to receive the central pin of the exploring electrode. Method of Use.-The chest is marked and prepared with electrode jelly in, the usual fashion. With the patient in the recumbent or semirecumbent position one of the weighted ends of the chest strap is tucked under the left back and the strap draped across the thorax so that the width of the strap covers all of the From the Department of Medicine and the Medical Research Laboratories. Beth Israel Hospital, and the Department of Medicine, Harvard Medical School. Boston, Mass. Received for publication April 16, 1947. “This is the type of tiylite which was used by the shoe industry during the war. The material was supplied for this study by the Phillips-Premier Corp., Boston, Mass. tThe “electronic welding” was done by ihe Victory Plastics Co., Hudson, Mass. 643

chest chest

Fig. l.-The two essential strap weighted at each electrode.

Fig.

%-The

chest

strap

parts of t,he apparatus. end, and on the left, the

and

plastic

block

holding

On

plastic

the

the right is shown block fitted over

electrode

arc shown

the the

transparent central

applied

pin

to the

plastic of the

chest.

marked positions and the free end lies on tht right chest or in the right axilia. The block is fixed to the exploring electrode which is connected to the appmpriate wire. The free end of the strap is lifted momentarily, the electrode is placed in position, the strap is replaced, and the tracing is recorded (Fig. 2). This proct>dure is repeated for each precordial position desired. The transparency of the strap and block makes it possible to see the location of the electrode at all times. When the electrode is in position, the strap rests snugly on the top of the block so as to clear the binding post and at the same time it hugs the chest and keeps the electrode in place. When taking electrocardiograms in Positions 5 and 6, especially if the breasts are pendulous, it may be advisable to place the left arm close to the side of the body. In Position 5 the elertrode and block will rest just anterior to the left arm, while in Position 6 the ;lrm will rest directly on the block.