diff --git a/server/client.js b/server/client.js
index 951ffd8aa..c7b3bc162 100644
--- a/server/client.js
+++ b/server/client.js
@@ -31,36 +31,19 @@ async function sendNotificationList(socket) {
  * @param toUser  True = send to all browsers with the same user id, False = send to the current browser only
  * @param overwrite Overwrite client-side's heartbeat list
  */
-async function sendHeartbeatList(socket, monitorID, toUser = false, overwrite = false, period = null) {
+async function sendHeartbeatList(socket, monitorID, toUser = false, overwrite = false) {
     const timeLogger = new TimeLogger();
 
-    let result;
+    let list = await R.getAll(`
+        SELECT * FROM heartbeat
+        WHERE monitor_id = ?
+        ORDER BY time DESC
+        LIMIT 100
+    `, [
+        monitorID,
+    ]);
 
-    if (period) {
-        let list = await R.getAll(`
-            SELECT * FROM heartbeat
-            WHERE monitor_id = ? AND
-            time > DATETIME('now', '-' || ? || ' hours')
-            ORDER BY time ASC
-        `, [
-            monitorID,
-            period,
-        ]);
-
-        result = list;
-
-    } else {
-        let list = await R.getAll(`
-            SELECT * FROM heartbeat
-            WHERE monitor_id = ?
-            ORDER BY time DESC
-            LIMIT 100
-        `, [
-            monitorID,
-        ]);
-
-        result = list.reverse();
-    }
+    let result = list.reverse();
 
     if (toUser) {
         io.to(socket.userID).emit("heartbeatList", monitorID, result, overwrite);
diff --git a/server/server.js b/server/server.js
index 4209b45c3..49e867da0 100644
--- a/server/server.js
+++ b/server/server.js
@@ -650,10 +650,23 @@ exports.entryPage = "dashboard";
 
                 console.log(`Get Monitor Beats: ${monitorID} User ID: ${socket.userID}`);
 
-                await sendHeartbeatList(socket, monitorID, true, true, period);
+                if (period == null) {
+                    throw new Error("Invalid period.");
+                }
+
+                let list = await R.getAll(`
+                    SELECT * FROM heartbeat
+                    WHERE monitor_id = ? AND
+                    time > DATETIME('now', '-' || ? || ' hours')
+                    ORDER BY time ASC
+                `, [
+                    monitorID,
+                    period,
+                ]);
 
                 callback({
-                    ok: true
+                    ok: true,
+                    data: list,
                 });
             } catch (e) {
                 callback({
diff --git a/src/components/PingChart.vue b/src/components/PingChart.vue
index 4818bba2f..0c76721cf 100644
--- a/src/components/PingChart.vue
+++ b/src/components/PingChart.vue
@@ -15,7 +15,7 @@
     </div>
 </template>
 
-<script>
+<script lang="ts">
 import { BarController, BarElement, Chart, Filler, LinearScale, LineController, LineElement, PointElement, TimeScale, Tooltip } from "chart.js";
 import dayjs from "dayjs";
 import utc from "dayjs/plugin/utc";
@@ -23,6 +23,7 @@ import timezone from "dayjs/plugin/timezone";
 import "chartjs-adapter-dayjs";
 import { LineChart } from "vue-chart-3";
 import { useToast } from "vue-toastification";
+import { UP, DOWN, PENDING } from "../util.ts";
 
 dayjs.extend(utc);
 dayjs.extend(timezone);
@@ -151,22 +152,28 @@ export default {
         chartData() {
             let pingData = [];  // Ping Data for Line Chart, y-axis contains ping time
             let downData = [];  // Down Data for Bar Chart, y-axis is 1 if target is down, 0 if target is up
-            if (this.monitorId in this.$root.heartbeatList) {
-                this.$root.heartbeatList[this.monitorId]
-                    .filter(
-                        (beat) => dayjs.utc(beat.time).tz(this.$root.timezone).isAfter(dayjs().subtract(Math.max(this.chartPeriodHrs, 6), "hours")))
-                    .map((beat) => {
-                        const x = this.$root.datetime(beat.time);
-                        pingData.push({
-                            x,
-                            y: beat.ping,
-                        });
-                        downData.push({
-                            x,
-                            y: beat.status === 0 ? 1 : 0,
-                        });
+
+            let heartbeatList = this.heartbeatList ||
+             (this.monitorId in this.$root.heartbeatList && this.$root.heartbeatList[this.monitorId]) ||
+             [];
+
+            heartbeatList
+                .filter(
+                    // Filtering as data gets appended
+                    // not the most efficient, but works for now
+                    (beat) => dayjs.utc(beat.time).tz(this.$root.timezone).isAfter(dayjs().subtract(Math.max(this.chartPeriodHrs, 6), "hours")))
+                .map((beat) => {
+                    const x = this.$root.datetime(beat.time);
+                    pingData.push({
+                        x,
+                        y: beat.ping,
                     });
-            }
+                    downData.push({
+                        x,
+                        y: beat.status === DOWN ? 1 : 0,
+                    });
+                });
+
             return {
                 datasets: [
                     {
@@ -197,14 +204,27 @@ export default {
         chartPeriodHrs: function (newPeriod) {
             if (newPeriod == "0") {
                 newPeriod = null;
+                this.heartbeatList = null;
+            } else {
+                this.$root.getMonitorBeats(this.monitorId, newPeriod, (res) => {
+                    if (!res.ok) {
+                        toast.error(res.msg);
+                    } else {
+                        this.heartbeatList = res.data;
+                    }
+                });
             }
-            this.$root.getMonitorBeats(this.monitorId, newPeriod, (res) => {
-                if (!res.ok) {
-                    toast.error(res.msg);
-                }
-            });
         }
     },
+    created() {
+        // Setup Watcher on the root heartbeatList,
+        // And mirror latest change to this.heartbeatList
+        this.$watch(() => this.$root.heartbeatList[this.monitorId], (heartbeatList) => {
+            if (this.chartPeriodHrs != 0) {
+                this.heartbeatList.push(heartbeatList.at(-1));
+            }
+        }, { deep: true });
+    }
 };
 </script>
 
@@ -217,7 +237,7 @@ export default {
 }
 
 .period-options {
-    padding: 0.3em 1.5em;
+    padding: 0.3em 2.2em;
     margin-bottom: -1.5em;
     float: right;
     position: relative;